Mission, the core of which was formerly known as Mission City, is a district municipality in the province of British Columbia, Canada. It is situated on the north bank of the Fraser River overlooking the Central Fraser Valley. Mission is the 23rd largest municipality in British Columbia, with a population of 34,505 (2006). Mission was incorporated in 1892.and is 225.78 kmĀ² in size. In 1922 the District of Mission was partitioned by the creation of the Village of Mission, which later became the Village of Mission City, then the Town of Mission City, until amalgamated with the District by plebiscite in 1969.

The more southerly portion of the municipality is bounded on the west by the lower reaches of the Stave River, which consists mostly of the lakewaters of two hydroelectric reservoirs, Stave Lake and Hayward Lake. Although the vast majority of the population of Mission lives well to the east of the Stave, over 50% of the northern land area of the municipality is west and north of that river; its extreme northwest corner is on the far side of upper Alouette Lake. A small portion of the lower Stave still runs free in its last two miles before its confluence with the Fraser at Ruskin; its last three-quarters of a mile forms the border with the larger municipality of Maple Ridge to the west.

Over 40% of Mission is actually tree farm, making it only one of two communities with municipal tree farms. (Revelstoke BC, with a much smaller and newer farm, is the second.) Mission's tree farm celebrated its 50th anniversary in 2008.

The eastern boundary of the municipality roughly coincides with the division between the Mission upland and the alluvial floodplain of Hatzic Prairie, which resembles much of the rest of the Fraser Valley Lowland. The unincorporated communities from Hatzic eastwards through Dewdney and Nicomen Island to Deroche are part of the social and commercial matrix centred on Mission but have never joined the municipality, as is also the case with areas north of Hatzic and Dewdney such as McConnell Creek and Durieu; the local economy and societies are built on dairy, berry and corn farming as well as a large First Nations community at Lakalhamen on Nicomen Island.