St Andrew's is an electoral ward in the London Borough of Havering. The ward has existed since the creation of the borough on 1 April 1965 and was first used in the 1964 elections. It returns three councillors to Havering London Borough Council.

The ward covers Hornchurch town centre and adjacent residential areas. The ward was dominated by the Conservative Party at the first eight elections. Since 1994, the Hornchurch Residents Association has been the most successful party to stand candidates.

The ward is named for St Andrew's Church, Hornchurch.

Councillors elected by party at each general borough election.

There was a revision of ward boundaries in Havering in 2022.^[1] The ward is bounded by the Romford-Upminster London Overground line to the north, The Ravensbourne and part of Abbs Cross Lane to the west, the District line of the London Underground to the south and the River Ingrebourne to the east. It includes Hornchurch town centre and the residential areas immediately to the north and south of it. Hornchurch tube station is on the boundary to the south and Upminster Bridge tube station is brought into the ward including the residential streets immediately to the south. The small section of northeastern Elm Park was removed from the ward.^[2][3]

There was a revision of ward boundaries in Havering in 2002.^[5] The St Andrew's ward occupied a triangle of land between the Romford to Upminster Line in the north to the District line in the south, and from the River Ingrebourne in the east to Harrow Lodge Park in the west.^[6] It included central Hornchurch and parts of the Elm Park and Upminster Bridge areas. From 6 May 2010 the ward formed part of the Hornchurch and Upminster UK Parliament constituency.

There was a revision of ward boundaries in Havering in 1978.^[12]

From 1979 the ward was part of the London East constituency for elections to the European Parliament and from 1999 to 2020 the London constituency.

St Andrew's ward has existed since the creation of the London Borough of Havering on 1 April 1965. For elections to Westminster it was part of the Hornchurch constituency and for elections to the Greater London Council it was part of the Havering electoral division from 1965 and then the Hornchurch electoral division from 1973.