The Kerala Legislative Assembly election of 1965 was held to elect members to the third Niyamasabha. Communist Party of India (Marxist), which was the splinter faction of Communist Party of India, emerged as the largest party in the assembly with 40 seats, followed by Indian National Congress with 36. However no single party could form a ministry commanding majority and hence this election is considered abortive. On March 25, President's rule was invoked for the fourth time.

The Communist Party of India (Marxist) (abbreviated as CPI(M)) is a communist political party in India. It is the largest communist party in India in terms of membership and electoral seats, and one of the national parties of India. The party was founded through a splitting from the Communist Party of India in 1964 and it quickly became the dominant fraction.