PRE-EFFECTIVE AMENDMENT NO. 4 TO THE FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NB Bancorp, Inc. Needham Bank 401(k) Plan (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Identification Number) As filed with the Securities and Exchange Commission on September 29, 2023 Registration No. 333-272567 UNITED STATES SECURITIES AND EXCHANGE COMMISSION W ...

Registration No. 333-272567 As filed with the Securities and Exchange Commission on September 1, 2023 (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Identification Number) Maryland 6036 93-2560883 1063 Great Plain Avenue Needham, Massachusetts 02492 (781) 444-2100 (Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant's Principal Executive Offices) Joseph P. Campanelli President, Chief E ...

As filed with the Securities and Exchange Commission on August 8, 2023 Registration No. 333-272567 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 PRE-EFFECTIVE AMENDMENT NO. 2 TO THE FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NB Bancorp, Inc. Needham Bank 401(k) Plan (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Ident ...

As filed with the Securities and Exchange Commission on July 27, 2023 Registration No. 333-272567 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 PRE-EFFECTIVE AMENDMENT NO. 1 TO THE FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NB Bancorp, Inc. Needham Bank 401(k) Plan (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Identi ...

Large accelerated filer ¨ Accelerated filer ¨ As filed with the Securities and Exchange Commission on June 9, 2023 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NB Bancorp, Inc. Needham Bank 401(k) Plan (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Iden ...