Exhibit 99.1

FOR IMMEDIATE RELEASE

Cogent Communications Reports Third Quarter Results and Increases its Regular Quarterly Dividend on its Common Stock by $0.025

Financial and Business Highlights

[WASHINGTON, D.C. November 4, 2021] Cogent Communications Holdings, Inc. (NASDAQ: CCOI) (“Cogent”) today announced service revenue of $147.9 million for the three months ended September 30, 2021, an increase of 0.03% from the three months ended June 30, 2021 and an increase of 4.0% from the three months ended September 30, 2020. Foreign exchange negatively impacted service revenue growth from the three months ended June 30, 2021 to the three months ended September 30, 2021 by $0.7 million and positively impacted service revenue growth from the three months ended September 30, 2020 to the three months ended September 30, 2021 by $0.6 million. On a constant currency basis, service revenue increased by 0.5% from the three months ended June 30, 2021 to the three months ended September 30, 2021 and grew by 3.6% from the three months ended September 30, 2020 to the three months ended September 30, 2021.

On-net service is provided to customers located in buildings that are physically connected to Cogent’s network by Cogent facilities. On-net revenue was $111.1 million for the three months ended September 30, 2021; an increase of 0.1% from the three months ended June 30, 2021 and an increase of 5.7% over the three months ended September 30, 2020.

Off-net customers are located in buildings directly connected to Cogent’s network using other carriers’ lit fiber optic facilities and services to provide the last mile portion of the link from the customers’ premises to Cogent’s network. Off-net revenue was $36.7 million for the three months ended September 30, 2021; a decrease of 0.1% from the three months ended June 30, 2021 and a decrease of 1.2% from the three months ended September 30, 2020.

Non-core services are legacy services, which Cogent acquired and continues to support but does not actively sell.

GAAP gross profit is defined as total service revenue less network operations expense, depreciation and amortization and equity-based compensation included in network operations expense. GAAP gross margin is defined as GAAP gross profit divided by total service revenue. GAAP gross profit increased by 3.8% from the three months ended September 30, 2020 to $68.7 million for the three months ended September 30, 2021 and decreased by 1.3% from the three months ended June 30, 2021. GAAP gross margin was 46.4% for the three months ended September 30, 2021, 46.5% for the three months ended September 30, 2020 and 47.1% for the three months ended June 30, 2021.

Excise taxes, including Universal Service Fund fees, recorded on a gross basis and included in service revenue and cost of network operations expense were $4.8 million for the three months ended September 30, 2021, $3.9 million for the three months ended September 30, 2020 and $4.8 million for the three months ended June 30, 2021.

Non-GAAP gross profit represents service revenue less network operations expense, excluding equity-based compensation and amounts shown separately (depreciation and amortization expense). Non-GAAP gross margin is defined as Non-GAAP gross profit divided by total service revenue. Non-GAAP gross profit increased by 3.8% from the three months ended September 30, 2020 to $91.4 million for the three months ended September 30, 2021 and decreased by 0.4% from the three months ended June 30, 2021. Non-GAAP gross profit margin was 61.8% for the three months ended September 30, 2021, 61.9% for the three months ended September 30, 2020 and 62.1% for the three months ended June 30, 2021.

Net cash provided by operating activities increased by 43.8% from the three months ended September 30, 2020 to $47.4 million for the three months ended September 30, 2021 and increased by 19.3% from the three months ended June 30, 2021.

Earnings before interest, taxes, depreciation and amortization (EBITDA) increased by 5.8% from the three months ended September 30, 2020 to $57.8 million for the three months ended September 30, 2021 and increased by 1.0% from the three months ended June 30, 2021. EBITDA margin was 39.0% for the three months ended September 30, 2021, 38.4% for the three months ended September 30, 2020 and 38.7% for the three months ended June 30, 2021.

Basic and diluted net income (loss) per share was $0.29 and $0.28 for the three months ended September 30, 2021, $(0.11) for the three months ended September 30, 2020 and $(0.05) for the three months ended June 30, 2021.

Unrealized and realized foreign exchange gains (losses) on Cogent’s 2024 Senior Euro Unsecured Notes were $10.2 million for the three months ended September 30, 2021, $(17.3) million for the three months ended September 30, 2020 and $(5.3) million for the three months ended June 30, 2021.

Total customer connections increased by 5.1% from September 30, 2020 to 92,991 as of September 30, 2021 and increased by 1.2% from June 30, 2021. On-net customer connections increased by 5.0% from September 30, 2020 to 80,162 as of September 30, 2021 and increased by 1.3% from June 30, 2021. Off-net customer connections increased by 5.5% from September 30, 2020 to 12,495 as of September 30, 2021 and increased by 0.9% from June 30, 2021.

The number of on-net buildings increased by 124 from September 30, 2020 to 3,008 as of September 30, 2021 and increased by 33 from June 30, 2021.

Quarterly Dividend Increase Approved

On November 2, 2021, Cogent’s Board approved a regular quarterly dividend of $0.830 per common share payable on December 3, 2021 to shareholders of record on November 19, 2021. This fourth quarter 2021 regular dividend represents a 3.1% increase of $0.025 per share from the third quarter 2021 regular dividend of $0.805 per share and an annual increase of 13.7% from the Q4 2020 dividend of $0.730 per share.

The payment of any future dividends and any other returns of capital will be at the discretion of the Board and may be reduced, eliminated or increased and will be dependent upon Cogent’s financial position, results of operations, available cash, cash flow, capital requirements, limitations under Cogent’s debt indenture agreements and other factors deemed relevant by the Board.

Impact of COVID-19

Cogent continues to be impacted by the COVID-19 pandemic and the accompanying responses by governments around the world. The recent spread of the Delta variant of COVID-19 has introduced new uncertainty.

The ongoing impact of the COVID-19 pandemic, including the spread of variant strains, and related government restrictions on Cogent’s business is unknown as a significant amount of uncertainty and volatility remains. Cogent does not know the ultimate scope and duration of the pandemic, the availability, efficacy and uptake of vaccines and therapeutic treatments, government actions that have been taken, or may be taken in the future in response to the pandemic and global economic conditions during and after the pandemic. Cogent has experienced a slight slowdown in the availability and delivery of networking equipment but Cogent believes it can adequately manage the operation, maintenance, upgrading and growth of its network. A worsening or prolonged slowdown may impact our ability to expand and augment our network. Cogent recently returned its employees in the United States back to its offices on a full-time basis and is planning on returning the rest of its employees outside of the United States to its offices on a full-time basis in the fourth quarter of 2021. Cogent is implementing measures to protect its workforce, but it can provide no assurance that these measures will be sufficient. Cogent’s decisions to require its employees to return to its offices on a full-time basis and to implement a COVID-19 vaccine mandate, where legally permitted, may impede its ability to retain existing employees or attract new employees. Moreover, Cogent’s results of operations may be adversely affected in the future as the pandemic and the related government restrictions continue or are reintroduced. Cogent may also experience slowdowns in new customer orders, find it difficult to collect from customers who are experiencing financial distress, undergo an increase in customer churn, encounter difficulties accessing the buildings and locations where Cogent installs new services and serves existing customers, or have difficulties procuring, shipping or installing necessary equipment on its network. Cogent may also find that its largest customer base, which is served primarily in its multi-tenant office buildings, may be adversely affected by falling demand for commercial office space in central business districts as companies located in these buildings elect not to return to their office space either on a temporary or even permanent basis or slow the pace of opening new offices. In addition, Cogent’s corporate customer base may reduce their overall number of locations due to adverse economic conditions or new working configurations which may adversely affect Cogent’s number of corporate connections and service revenues. As a result, the global economic impact of the COVID-19 pandemic may have prolonged effects that impact Cogent’s business well into the future. These and other risks are described in more detail in Cogent’s Annual Report on Form 10-K for the year ended December 31, 2020 and our Form 10-Q for the quarters ended March 31, 2021, June 30, 2021 and September 30, 2021.

Conference Call and Website Information

Cogent will host a conference call with financial analysts at 8:30 a.m. (ET) on November 4, 2021 to discuss Cogent’s operating results for the third quarter of 2021 and to discuss Cogent’s expectations for full year 2021. Investors and other interested parties may access a live audio webcast of the earnings call in the “Events” section of Cogent’s website at www.cogentco.com/events. A replay of the webcast, together with the press release, will be available on the website following the earnings call. A downloadable file of Cogent’s “Summary of Financial and Operational Results” and a transcript of its conference call will also be available on Cogent’s website following the conference call.

About Cogent Communications

Cogent Communications (NASDAQ: CCOI) is a multinational, Tier 1 facilities-based ISP. Cogent specializes in providing businesses with high-speed Internet access, Ethernet transport, and colocation services. Cogent’s facilities-based, all-optical IP network backbone provides services in 215 markets globally.

Cogent Communications is headquartered at 2450 N Street, NW, Washington, D.C. 20037. For more information, visit www.cogentco.com. Cogent Communications can be reached in the United States at (202) 295-4200 or via email at info@cogentco.com.

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COGENT COMMUNICATIONS HOLDINGS, INC., AND SUBSIDIARIES

Summary of Financial and Operational Results

Schedules of Non-GAAP Measures

EBITDA and EBITDA, as adjusted

EBITDA represents net cash flows provided by operating activities plus changes in operating assets and liabilities, cash interest expense and cash income tax expense. Management believes the most directly comparable measure to EBITDA calculated in accordance with generally accepted accounting principles in the United States, or GAAP, is net cash provided by operating activities. The Company also believes that EBITDA is a measure frequently used by securities analysts, investors, and other interested parties in their evaluation of issuers. EBITDA, as adjusted, represents EBITDA plus net gains (losses) on asset related transactions.

The Company believes that EBITDA, and EBITDA, as adjusted, are useful measures of its ability to service debt, fund capital expenditures and expand its business. EBITDA, and EBITDA, as adjusted are an integral part of the internal reporting and planning system used by management as a supplement to GAAP financial information. EBITDA, and EBITDA, as adjusted are not recognized terms under GAAP and accordingly, should not be viewed in isolation or as a substitute for the analysis of results as reported under GAAP, but rather as a supplemental measure to GAAP. For example, these metrics are not intended to reflect the Company’s free cash flow, as it does not consider certain current or future cash requirements, such as capital expenditures, contractual commitments, and changes in working capital needs, interest expenses and debt service requirements. The Company’s calculations of these metrics may also differ from the calculations performed by its competitors and other companies and as such, its utility as a comparative measure is limited.

EBITDA, and EBITDA, as adjusted, are reconciled to net cash provided by operating activities in the table below.

Constant currency revenue is reconciled to service revenue as reported in the tables below.

Constant currency impact on revenue changes – sequential periods

Constant currency impact on revenue changes – prior year periods

Non-GAAP gross profit and Non-GAAP gross margin

Non-GAAP gross profit and Non-GAAP gross margin are reconciled to GAAP gross profit and GAAP gross margin in the table below.

Gross and Net Leverage Ratios

Gross leverage ratio is defined as total debt divided by the trailing last 12 months EBITDA, as adjusted. Net leverage ratio is defined as total net debt (total debt minus cash and cash equivalents) divided by the trailing last 12 months EBITDA, as adjusted. Cogent’s gross leverage ratio and net leverage ratio are shown below.

Cogent’s SEC filings are available online via the Investor Relations section of www.cogentco.com or on the Securities and Exchange Commission’s website at www.sec.gov.

COGENT COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED BALANCE SHEETS

AS OF SEPTEMBER 30, 2021 AND DECEMBER 31, 2020

(IN THOUSANDS, EXCEPT SHARE DATA)

COGENT COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2021 AND SEPTEMBER 30, 2020

(IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)

COGENT COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2021 AND SEPTEMBER 30, 2020

(IN THOUSANDS, EXCEPT SHARE AND PER SHARE AMOUNTS)

COGENT COMMUNICATIONS HOLDINGS, INC., AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2021 AND SEPTEMBER 30, 2020

(IN THOUSANDS)

COGENT COMMUNICATIONS HOLDINGS, INC. AND SUBSIDIARIES

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2021 AND SEPTEMBER 30, 2020

(IN THOUSANDS)

Except for historical information and discussion contained herein, statements contained in this release constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to statements identified by words such as “believes,” “expects,” “anticipates,” “estimates,” “intends,” “plans,” “targets,” “projects” and similar expressions. The statements in this release are based upon the current beliefs and expectations of Cogent’s management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements. Numerous factors could cause or contribute to such differences, including the impact of the COVID-19 pandemic and the related government policies; future economic instability in the global economy or a contraction of the capital markets which could affect spending on Internet services and our ability to engage in financing activities; the impact of changing foreign exchange rates (in particular the Euro to USD and Canadian dollar to USD exchange rates) on the translation of our non-USD denominated revenues, expenses, assets and liabilities; legal and operational difficulties in new markets; the imposition of a requirement that we contribute to the US Universal Service Fund on the basis of our Internet revenue; changes in government policy and/or regulation, including net neutrality rules  by the United States Federal Communications Commission and in the area of data protection; cyber-attacks or security breaches of our network; increasing competition leading to lower prices for our services; our ability to attract new customers and to increase and maintain the volume of traffic on our network; the ability to maintain our Internet peering arrangements on favorable terms; our reliance on an equipment vendor, Cisco Systems Inc., and the potential for hardware or software problems associated with such equipment; the dependence of our network on the quality and dependability of third-party fiber providers; our ability to retain certain customers that comprise a significant portion of our revenue base; the management of network failures and/or disruptions; and outcomes in litigation as well as other risks discussed from time to time in our filings with the Securities and Exchange Commission, including, without limitation, our Annual Report on Form 10-K for the year ended December 31, 2020 and our Form 10-Q for the quarters ended March 31, 2021, June 30, 2021 and September 30, 2021. Cogent undertakes no duty to update any forward-looking statement or any information contained in this press release or in other public disclosures at any time.

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