Rajapur Vidhan Sabha constituency (Marathi: राजापूर विधान सभा मतदारसंघ) is one of the 288 Vidhan Sabha (legislative assembly) constituencies of Maharashtra state in western India.
Rajapur constituency is one of the five Vidhan Sabha constituencies located in the Ratnagiri district. It comprises the entire Rajapur and Lanja tehsils and part of Sangameshwar tehsil of the district.
Rajapur is part of the Ratnagiri-Sindhudurg Lok Sabha constituency along with five other Vidhan Sabha segments, namely Ratnagiri and Chiplun in Ratnagiri district and Kankavli, Kudal and Sawantwadi in the Sindhudurg district.