The Great River) is a 1994 Indian Tamil-language crime drama film directed by Santhana Bharathi and co-written by Kamal Haasan.

The film stars Haasan and Sukanya, with S. N. Lakshmi, Tulasi, Shobana Vignesh, Dinesh, Poornam Viswanathan, Rajesh and V. M. C. Haneefa in supporting roles.

The idea for Mahanadhi originated when Haasan discovered his domestic help's plan to kidnap his daughters for a ransom.

Krishnaswamy is a widower living peacefully with his mother-in-law Saraswathi Ammal, daughter Kaveri and son Bharani in a village near Kumbakonam.

He meets Dhanush, a con artist from Madras, who lusts for Krishna's prosperity and asks him to join his chit fund business.

Due to unavoidable situations, Saraswathi dies, and Krishna learns that his children have gone missing as well after being released from prison.

On a walk with Panjapakesan, Krishna finds Bharani working with a family of street performers, and brings him home.

According to Kamal Haasan, his domestic help plotted to kidnap his daughters for a ransom, but he discovered their plan.

[14][1] Cheran worked as an associate director,[15] but left the project midway due to "creative differences" with Haasan.

[10]: 16:50–17:08  Sivasankar, who became known as "Mahanadhi" Shankar, was cast as the prison warden Thulukaanam as the makers wanted someone who could perform stunts as well as act.

[10]: 17:55–18:40  V. M. C. Haneefa readily agreed to act in the film as Dhanush when approached; he had previously been considered for an antagonistic role in Bharathi's Gunaa (1991).

The woman reuniting Krishnaswamy with his daughter was played by a bank officer then associated with the Tamil sangam theatre troupe.

[10]: 21:00–21:20 Principal photography was to have begun in May 1993, but began only in September due to casting difficulties; Bharathi said the makers "had to reach for three boys belonging to different age groups and son resembling Kamal [Haasan] and three girls likewise to play Kamal's daughters".

[6] Baradwaj Rangan said, "Mahanadhi is one of the saddest films ever made, grim north to Singin' in the Rain's blithe south, but it has an extraordinary musical moment in 'Peygala nambaadhey', which Kamal Haasan's character sings, during a power cut, to his children who are scared of the dark".

He described the song as "(a) a father's moral instruction to his children ("face your fears"), (b) a bit of levity, (c) a sweet stretch showcasing this family's dynamics, and (d) a hint that bad things can come at you from everywhere, whether from the television set (featuring terrifyingly distorted musical performers) or even a doting grandmother (who, jokingly, fashions herself into a demon goddess).

[19] Poet Puviarasu stated: "Don't go after the mystic deer, was Kamal's message in the movie Mahanadhi [...] In the film, Krishna relocates to the city to earn more money, own a Benz and educate his daughter at Church Park Convent.

[31] Despite clashing against other Pongal releases such as Sethupathi IPS, Amaidhipadai, Rajakumaran, Veetla Visheshanga, Siragadikka Aasai and Sindhu Nathi Poo, it became a box office success.

[29] In September 2020, Rajesh, who played a supporting role in the film, told Nakkheeran that the successful box office run and profits made by Mahanadhi helped Rajkannu clear all his earlier debts and it was he who requested Haasan to make the film for Rajkannu.