Arunachalam is a 1997 Indian Tamil-language action drama film directed by Sundar C and written by Crazy Mohan. The film stars Rajinikanth as the title character as well as in a dual role, alongside Soundarya and Rambha, with Jaishankar, Ravichandran and Visu in supporting roles. It revolves around a village simpleton, who later discovers he is the heir of a deceased billionaire, but must face extreme challenges to claim his father's inheritance.

The film is loosely based on the 1902 George Barr McCutcheon novel Brewster's Millions. The soundtrack and background score were composed by Deva, while U. K. Senthil Kumar handled the cinematography and P. Sai Suresh did so for editing.

Arunachalam was released on 10 April 1997 and became a box office success. It won three Tamil Nadu State Film Awards, including Best Film.