Bank of Montreal

Foreign Filer Report • Dec 15, 2025

6-K 1 d78523d6k.htm 6-K 6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

of the Securities Exchange Act of 1934

For the month of: December, 2025

Commission File Number: 001-13354

BANK OF MONTREAL

(Name of Registrant)

100 King Street West 1 First Canadian Place Toronto, Ontario Canada, M5X 1A1 ( Executive Offices ) 129 rue Saint-Jacques Montreal, Quebec Canada, H2Y 1L6 ( Head Office )

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ☐ Form 40-F ☒

INCORPORATION BY REFERENCE

The information contained in this Form 6-K and any exhibits hereto shall be deemed filed with the Securities and Exchange Commission (“SEC”) solely for purposes of incorporation by reference into and as part of the following registration statement of the registrant on file with and declared effective by the SEC:

1. Registration Statement – Form F-3 – File No. 333-285508

EXHIBIT INDEX

Exhibit	Description of Exhibit
5.1	Opinion of Sullivan & Cromwell LLP, U.S. counsel to the Bank.
5.2	Opinion of Osler, Hoskin & Harcourt LLP, Canadian counsel to the Bank.
23.1	Consent of Sullivan & Cromwell LLP (included in Exhibit 5.1 above).
23.2	Consent of Osler, Hoskin & Harcourt LLP (included in Exhibit 5.2 above).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

By: /s/ Paras Jhaveri Name: Paras Jhaveri Title:   Global Head, Capital and Funding
Date : December 15, 2025