David Cook (Northern Ireland politician)

David Sommerville Cook (born 1943/1944) is a former politician in Northern Ireland.

Cook works as a solicitor, eventually becoming a senior partner at Sheldon and Stewart Solicitors.

In 1970, Cook was a founder member of the Alliance Party of Northern Ireland (APNI), while he was elected to the party's Central Executive in 1971.

He was elected to Belfast City Council in 1973, a position he held until 1985. In 1978, he became the first non-Unionist Lord Mayor of Belfast since William James Pirrie, a Home Rule Liberal, in 1896–1898.

He stood for APNI in Belfast South in the February 1974 general election, taking just under 10% of the vote. He was able to improve to 27% of the vote at the Belfast South by-election, 1982. Following this, he won a seat on the Northern Ireland Assembly representing Belfast South.

In the 1983 general election, 1986 by-election and 1987 general election, he consistently won over 20% of the votes cast in Belfast South. He also stood for Alliance in the 1984 European Parliament election, but took only 4% of the vote. From 1980–84, Cook served as the Deputy Leader of APNI.