Upminster was an electoral division for the purposes of elections to the Greater London Council.

The fourth election to the GLC (and first using revised boundaries) was held on 12 April 1973.

This was extended for an extra year in 1976 when the electoral cycle was switched to four-yearly.

The sixth and final election to the GLC (and third using revised boundaries) was held on 7 May 1981.

The councillor was elected for a four-year term, extended by an extra year by the Local Government (Interim Provisions) Act 1984, ahead of the abolition of the council.