Lower Bay station is nestled directly beneath Bay station on Toronto's Yonge-University subway line. In use for only six months during 1966, it is a remainder from the TTC's attempt to divert trains in an awkward loop from the northbound University line to the eastbound Danforth line.

In September 1966, it was abandoned. The doorways to the station have since been bricked over and Lower Bay is only accessible via unmarked fire doors. The station is closed to the public, though it is often used for commercial ventures like film and TV shoots and has been included in festivals like Nuit Blanche and Doors Open Toronto.

For a few months in 2007, trains were diverted through Lower Bay station and commuters were able to see it for the first time in 41 years.