One of two Presbyterian churches on Queen's Square! The congregations merged recently so I guess this one is not a Presbyterian Church anymore, but it was built as one back in the 1860s.
This building was designed in the Victorian Gothic style by James Smith of Toronto and built by a local builder called Lewis (Ludwig) Kribs. The bell in the steeple was shipped to Canada from Scotland.
In my photo of the river from a few days earlier, the steeple of this church can be seen on the left side of the photo.