Rainham was an electoral ward in the London Borough of Havering from 1965 to 2002. The ward was first used in the 1964 elections. It returned councillors to Havering London Borough Council.
There was a revision of ward boundaries in Havering in 1978. There was a very minor adjustment of the ward boundaries on 1 April 1994.
The election on 7 May 1998 took place on the same day as the 1998 Greater London Authority referendum.
The election took place on 5 May 1994.
The election took place on 3 May 1990.
The by-election took place on 20 April 1989, following the resignations of Mary Ball and Laraine Saunders.
The election took place on 8 May 1986.
The by-election took place on 26 September 1985, following the resignation of Paul Long.
The by-election took place on 14 April 1983, following the death of Mary Davies.
The election took place on 6 May 1982.
The election took place on 4 May 1978.
The election took place on 2 May 1974.
The election took place on 13 May 1971.
The election took place on 9 May 1968.
The election took place on 7 May 1964.