Inaugurated in 2018, the G. Karthikeyan Legislature Museum is located behind the Legislative Assembly of Kerala and is within the same compound. This museum is dedicated to the history of the political setup of the state of Kerala, with special emphasis on the legislative assembly. The museum is spread out over two floors and three galleries. Each gallery has been filled with artefacts related to different aspects of the state and its formation. The museum has a special gallery reserved for a collection of photographs of the swearing-in ceremonies of the chief ministers of Kerala from the time of its formation.

Photographs of ministers have been hung along the corridor and the stairs in chronological order of their periods of office. The first gallery contains a number of interactive kiosk platforms, each focusing on a particular part of the history; for instance, there is one with the history of the assembly, the list of speakers, list of cabinet members, list of female members, the voting system, the history of voting, and so on. There is also a gallery focusing on Mahatma Gandhi, which contains photographs, copies of his books, newspaper clippings, etc. The last gallery displays the gift items that Mr A.K. Antony had received during his tenure as defence minister. The collection is quite large and gives a glimpse into the social norms followed in the political realm.