Arunachalam is a 1997 Indian Tamil-language masala film directed by Sundar C and written by Crazy Mohan.

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 soundtrack and background score were composed by Deva, while U. K. Senthil Kumar handled the cinematography and P. Sai Suresh did so for editing.

In Alanganallur, Arunachalam, a respected young headman, resides with his parents, Ammayappan and Janaki, three younger siblings, Saravanan, Sakthivel, and sister Arundhati, while their grandmother, Vedhavalli is a stern matriarch, who takes pride in their ancestral lineage.

Umayal's teenage daughter, Vedhavalli, named after her grandmother, is impressed by Arunachalam's reputation among the villagers.

It is revealed that Meenakshiyammal, Arunachalam's biological mother, handed over her newborn son to Ammayappan on her deathbed.

In Madras, Arunachalam meets Beeda Kathavarayan, who offers him a job and soon befriends Nandhini, the daughter of an honest businessman Rangachari.

He rents a five-star hotel, and cars, participates in horse racing, buys lottery tickets, and invests in film production, casting his friend Arivazhagan as the lead actor.

Also, Arunachalam's relationship with Vedhavalli becomes strained as he cannot lend her money due to the conditions and also being unable to disclose the reason to her.

After the success of Muthu in 1995, Rajinikanth took a year out dabbling in politics and taking a sabbatical before announcing that his next film would be Arunachalam written by Crazy Mohan.

It was indicated that some of the people who the film would go on to cause benefits for included Kalakendra Govindharajan who introduced Rajinikanth in his production Apoorva Raagangal (1975), Kalaignyanam who featured Rajinikanth in the lead role for the first time with his production Bairavi (1978) and brothers Ramji and Babji who produced some of the actor's early hits, Kaali (1980) and Garjanai (1980).

Furthermore, collections would also be shared between the family of Sathya Studio Padmanabhan, actress Pandari Bai, actor V. K. Ramasamy and producer Madurai Nagaraja.

[3] Manorama was also added to the cast, surprising some media as she had caused controversy the previous year by lashing out at Rajinikanth's political motives.

[11] The Hindu wrote on 18 April, "Arunachalam contains all the elements that provide escapist entertainment [...] humour, fairplay, love, feud occupy the frames".

[13] R. P. R. of Kalki gave a negative review, panning the weak screenplay, many of the montage shots after interval in bits and pieces, Crazy Mohan's dialogues lacking humour, Deva's music though he praised Rajinikanth's acting for rescuing the film but the technicians seems to have let him down and concluded Arunachalam did not do it despite the Lord saying that he should give great happiness to the fans in this Tamil New Year.