The ward covers Hornchurch town centre and adjacent residential areas.

[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.

[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.

[9] The by-election took place on 4 June 2009, following the resignation of David Charles of the Conservative Party.

[9] The by-election took place on 14 June 2007, following the resignation of Brenda Riddle of the Hornchurch Residents Association.

[18] 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.

It was first used in the 1964 election to Havering London Borough Council, with an electorate of 8,695 returning three councillors.