Filed Pursuant to Rule 424(b)(3)
Registration Statement No. 333-217200

Prospectus Addendum to the Prospectus Supplement dated September 23, 2018 and

the accompanying Prospectus dated April 27, 2017.

Senior Medium-Term Notes

Bank of Montreal or any of its affiliates, including BMO Capital Markets Corp., may use this prospectus addendum, the accompanying prospectus supplement dated September 23, 2018 relating to Medium-Term Notes, Series E, and the accompanying prospectus dated April 27, 2017 in connection with market-making transactions of notes that were originally issued under a similar prospectus supplement for Senior Medium-Term Notes with a date earlier than September 23, 2018, and a similar prospectus, with a date earlier than April 27, 2017. We refer below to such earlier prospectus supplement as the “earlier prospectus supplement” and such earlier prospectus as the “earlier prospectus”.

When this prospectus addendum, the accompanying prospectus supplement dated September 23, 2018 relating to Medium-Term Notes, Series E, and the accompanying prospectus dated April 27, 2017 are used in connection with a market-making transaction, you should note that the accompanying prospectus supplement dated September 23, 2018 relating to Medium-Term Notes, Series E, supersedes the earlier prospectus supplement, and the accompanying prospectus dated April 27, 2017 supersedes the earlier prospectus. When you read the prospectus supplement or pricing supplement with the specific terms of the offered notes, please note that all references in it to the earlier prospectus supplement should instead refer to the accompanying prospectus supplement dated September 23, 2018 relating to Medium-Term Notes, Series E, and all references in it to the earlier prospectus should instead refer to the accompanying prospectus dated April 27, 2017.

You should read the terms of the accompanying prospectus supplement or pricing supplement, which describes the specific terms of the offered notes, together with the accompanying prospectus supplement dated September 23, 2018 relating to Medium-Term Notes, Series E, and the accompanying prospectus dated April 27, 2017.

The offered notes are our unsecured obligations and are not savings accounts or deposits that are insured by the United States Federal Deposit Insurance Corporation, the Deposit Insurance Fund, the Canada Deposit Insurance Corporation or any other governmental agency or instrumentality or other entity.

Prospectus Addendum dated September 23, 2018