The 1991 Kerala Legislative Assembly election was held on 18 June 1991 to elect members to the Niyamasabha. The incumbent LDF government, which was in power from 1987, decided to seek a fresh mandate one year ahead of the expiry of its term. The decision was prompted by the announcement of the elections to the Lok Sabha and the Front's good showing in the elections to the local bodies held in the previous year.

Erambala Krishnan Nayanar was an Indian politician who served as the 9th chief minister of Kerala from 1980 to 1981, 1987 to 1991 and again from 1996 to 2001. He served in that position for a total of 10 years, 11 months and 22 days, thus making him the longest-served Chief Minister of Kerala. He was a senior leader of the Communist Party of India (Marxist).