Mission is a city in the Lower Mainland of the province of British Columbia, Canada. It was originally incorporated as a district municipality in 1892, growing to include additional villages and rural areas over the years, adding the original Town of Mission City, along an independent core of the region, in 1969. It is bordered by the city of Abbotsford to the south and the city of Maple Ridge to the west. To the east are the unincorporated areas of Hatzic and Dewdney.

It is situated on the north bank of the Fraser River, backing onto mountains and lakes overlooking the Central Fraser Valley 65 km (40 miles) southeast of Vancouver.

Unlike the other Fraser Valley municipalities, Mission is mostly forested upland with only small floodplains lining the shore of the Fraser River. Some benches of farmland rise in succession northwards above the core developed area of the city. Mission was once the heart of the berry industry in the Fraser Valley, with "Home of the Big Red Strawberry" as Mission's slogan in the 1930s and into the 1940s.

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 tree farm, making it one of two communities with municipal tree farms (the other being Revelstoke, with a much smaller and newer farm). Mission's tree farm celebrated its 50th anniversary in 2008. It comprises much of the northern part of the district, including the area west of the Stave River, up to the district's northern boundary near the foot of Mount Robie Reid; a small sliver of Mission District is at the head of Alouette Lake (normally thought of as being in Maple Ridge).

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 the Indian Reserves of the Leq' a: mel First Nation, formerly known as the Lakahahmen First Nation, on Nicomen Island and Deroche.

Mission was incorporated in 1892 and is 225.78 km² (87.17 sq mi) 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 City of Mission uses the current Council-Manager system of local government. The present Council, was elected on October 15, 2022. The current mayor is Paul Horn. A notable past mayor is Pam Alexis who resigned as the mayor of Mission in November 2020 after winning a seat for the provincial riding of Abbotsford-Mission in the Legislative Assembly of British Columbia.