The fourth election to South Glamorgan County Council was held in May 1985.
There were a smaller number of Plaid Cymru and Green Party candidates and a few Independents.
Following boundary changes, two sitting members opposed each other in the Cornerswell, Landsdowne and Llandaff North wards.
Some of the seats where Alliance candidates were successful had the highest turnouts in the county.
Among other seats, one of the highest turnouts (59.6%) was in the Rhoose with Llancarfan ward where the sitting councillor, elected as a Conservative in 1981, stood as an Independent but finished bottom of the poll.