Exhibit 99.1

NEWS RELEASE

FOR IMMEDIATE RELEASE

Phone:     781-393-4630

Fax:     781-393-4071

CENTURY BANCORP, INC. ANNOUNCES INCREASED EARNINGS FOR Q1 2018, UP

SIGNIFICANTLY, 26.5%; ASSETS AT $4.8 BB; REGULAR DIVIDEND DECLARED

Medford, MA, April 10, 2018 — Century Bancorp, Inc. (NASDAQ:CNBKA) (www.centurybank.com) (“the Company”) today announced net income of $7,709,000 for the quarter ended March 31, 2018, or $1.38 per Class A share diluted, an increase of 26.5% compared to net income of $6,096,000, or $1.09 per Class A share diluted, for the same period a year ago. Total assets decreased 0.2% from $4.79 billion at December 31, 2017 to $4.78 billion at March 31, 2018.

Net interest income totaled $22.5 million for the quarter ended March 31, 2018 compared to $20.5 million for the same period in 2017. The 9.8% increase in net interest income for the period is primarily due to an increase in average earning assets and an increase in the net interest margin. The net interest margin increased from 2.16% on a fully taxable equivalent basis in 2017 to 2.19% for the same period in 2018. This was primarily the result of an increase in rates on earning assets. The average balances of earning assets increased by 1.8% combined with a similar increase in average deposits. Also, interest expense increased 44.9% primarily as a result of an increase in rates on deposit balances.

The Company’s effective tax rate increased from 2.3% for the first quarter of 2017 to 6.1% for the same period in 2018, primarily as a result of an increase in taxable income offset, somewhat, by a decrease in the federal tax rate from 34% to 21% as a result of the Tax Cuts and Jobs Act.

At March 31, 2018, total equity was $268.2 million compared to $260.3 million at December 31, 2017. The Company’s equity increased primarily as a result of earnings, offset somewhat by dividends paid.

The Company’s leverage ratio stood at 6.77% at March 31, 2018, compared to 6.70% at December 31, 2017. The increase in the leverage ratio was due to an increase in stockholders’ equity, offset somewhat by an increase in quarterly average assets. Book value as of March 31, 2018 was $48.17 per share compared to $46.75 at December 31, 2017.

The Company’s allowance for loan losses was $26.7 million or 1.22% of loans outstanding at March 31, 2018, compared to $26.3 million or 1.21% of loans outstanding at December 31, 2017, and $24.8 million or 1.22% of loans outstanding at March 31, 2017. The ratio of the allowance for loan losses to loans outstanding has remained relatively stable. Non-performing assets totaled $1.4 million at March 31, 2018, compared to $1.7 million at December 31, 2017 and $810,000 at March 31, 2017.

The Company’s Board of Directors voted a regular quarterly dividend of 12.00 cents ($0.12) per share on the Company’s Class A common stock, and 6.00 cents ($0.06) per share on the Company’s Class B common stock. The dividends were declared payable May 15, 2018 to stockholders of record on May 1, 2018.

The Company, through its subsidiary bank, Century Bank and Trust Company, a state chartered full service commercial bank, operating twenty-seven full-service branches in the Greater Boston area, offers a full range of Business, Personal and Institutional Services.

Century Bank and Trust Company is a member of the FDIC and is an Equal Housing Lender.

This press release contains certain “forward-looking statements” with respect to the financial condition, results of operations and business of the Company. Actual results may differ from those contemplated by these statements. The Company wishes to caution readers not to place undue reliance on any forward-looking statements. The Company disclaims any intent or obligation to update publicly any such forward-looking statements, whether in response to new information, future events or otherwise.

Century Bancorp, Inc. and Subsidiaries

Consolidated Comparative Statements of Condition (unaudited)

(in thousands)

Century Bancorp, Inc. and Subsidiaries

Consolidated Comparative Statements of Income (unaudited)

For the Quarter ended March 31, 2018 and 2017

(in thousands)

Century Bancorp, Inc. and Subsidiaries

Consolidated Year-to-Date Average Comparative Statements of Condition (unaudited)

(in thousands)

Century Bancorp, Inc. and Subsidiaries

\Consolidated Selected Key Financial Information (unaudited)

(in thousands, except share data)