Pier 21 is a former ocean liner terminal and immigration shed from 1928 to 1971 in Halifax, Nova Scotia, Canada. Nearly one million immigrants came to Canada through Pier 21, and it is the last surviving seaport immigration facility in Canada. The facility is often compared to the landmark American immigration gateway Ellis Island. The former immigration facility is now occupied by the Canadian Museum of Immigration, the Nova Scotia College of Art and Design as well as various retail and studio tenants.

The Canadian Museum of Immigration at Pier 21, in Halifax, Nova Scotia, is Canada's national museum of immigration. The museum occupies part of Pier 21, the former ocean liner terminal and immigration shed from 1928 to 1971. Pier 21 is Canada's last remaining ocean immigration shed. The facility is often compared to Ellis Island (1892–1954), in terms of its importance to mid-20th-century immigration to Canada an association it shares with 19th century immigration history at Grosse Isle, Quebec (1832–1932) and Partridge Island in Saint John, New Brunswick (1785–1941). The museum began as an independent institution run by the Pier 21 Society in 1999. It became a national museum run by the Canadian federal government in 2011.