Along with paintings, prints, works on paper, and sculpture, the museum's collection includes decorative art, archival material, and rare books, assembled by Samuel E. Weir.

[1] In the RiverBrink collection are paintings by many of Canada's most significant artists, including Tom Thomson, Homer Watson, Marc Aurèle de Foy Suzor-Coté, Cornelius Krieghoff, Emily Carr, and members of the Group of Seven.

The collection also contains artwork by well-known British, French, and American artists, such as Augustus John, Mary Cassatt, Armand Guillaumin, Grant Wood, and Edgar Degas, among others.

The museum has a large collection of decorative arts, including English and Québec silver, clocks, antique furniture, Indian medals, coins, rugs and ceramics.

In addition, RiverBrink's library and archives hold over 4,000 books, personal correspondence, maps, auction house records, and individual files of several hundred artists.