The Grammar School Lagoon Boat Ramp is a concrete boat ramp situated on the north side of Geelong, on the Melbourne side of the city, providing access to Grammar School Lagoon at the northern tip of Corio Bay's inner harbour.

The lagoon takes its name from its proximity to Geelong Grammar School and features shallow weed flats along with deeper sections occupied by the Lagoon Boat Club and numerous swing-moored yachts.

Reviewers note the ramp is considered one of the lesser-rated launch options in the Geelong area. Kayak anglers also use the area, with an alternative beach launch near the boat club jetty offering more direct access to the swing moorings.