Terrestrial Energy Files $500M Mixed-Securities Shelf Prospectus

TERRESTRIAL ENERGY INC.

Prospectus

$500,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

Rights

Units

This prospectus relates to common stock, preferred stock, debt securities, warrants, rights and units that Terrestrial Energy Inc. may sell from time to time in one or more offerings on terms to be determined at the time of sale. We refer to the common stock, preferred stock, debt securities, warrants, rights and units collectively as the "securities."  We will provide specific terms of these securities in supplements to this prospectus. You should read this prospectus and any supplement carefully before you invest. This prospectus may not be used to offer and sell securities unless accompanied by a prospectus supplement for those securities.

These securities may be sold directly by us, through dealers or agents designated from time to time, to or through underwriters or through a combination of these methods. See "Plan of Distribution" in this prospectus. We may also describe the plan of distribution for any particular offering of these securities in any applicable prospectus supplement. If any agents, underwriters or dealers are involved in the sale of any securities in respect of which this prospectus is being delivered, we will disclose their names and the nature of our arrangements with them in a prospectus supplement. The net proceeds we expect to receive from any such sale will also be included in a prospectus supplement.