NB Bancorp, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐Preliminary Proxy Statement

☐Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☒Definitive Proxy Statement

☐Definitive Additional Materials

☐Soliciting Material Pursuant to § 240.14a-12

NB Bancorp, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

☒No fee required.

☐Fee paid previously with preliminary materials.

☐Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

$5.2b

Assets

$1.8m

Annual Giving

Build something lasting.

Build something special.

Build something with us.

+22%

Net Interest
Income

59%

Efficiency Ratio

+21%

Core Deposit
Growth

SEC Form DEF 14A filed by NB Bancorp Inc.