Alathur State assembly constituency is one of the 140 state legislative assembly constituencies in Kerala in southern India. It is also one of the seven state legislative assembly constituencies included in Alathur Lok Sabha constituency. As of the 2021 Assembly elections, the current MLA is K. D. Prasenan of CPI(M).

Alathur Assembly constituency is composed of the following local self-governed segments:

The following list contains all members of Kerala Legislative Assembly who have represented Alathur Niyamasabha Constituency during the period of various assemblies:

Percentage change (±%) denotes the change in the number of votes from the immediate previous election.

There were 165,294 registered voters in Alathur Constituency for the 2016 election.

There were 152,827 registered voters in the constituency for the 2011 election.

There were 157,841 registered voters in the constituency for the 2006 election.

There were 154,832 registered voters in the constituency for the 2001 election.