Saravanavelu alias Velu (Vijay), is a state-level kabaddi player who is the son of Chennai's Assistant Commissioner of Police Sivasubramanian (Ashish Vidyarthi). Sivasubramanian is not fond of his son, constantly chiding him for his lack of interest in studies and his love for kabaddi. In contrast, his mother (Janaki Sabesh) dotes on him and his younger sister Bhuvana (Nancy Jennifer), a sharp and inquisitive schoolgirl, constantly gets Velu into trouble with their father, but nevertheless adores him.
Meanwhile in Madurai, there is a ruthless factionalist leader Muthupandi (Prakash Raj), who is obsessed with Dhanalakshmi (Trisha) and would do anything to marry her. Muthupandi kills Dhanalakshmi's elder brother as he rejects his offer to marry her. Then Dhanalakshmi’s younger brother is also killed by Muthupandi when he tries to avenge his brother's murder. Dhanalakshmi’s father (Vinod Raj) is a meek person who gets horrified by Muthupandi’s acts and asks Dhanalakshmi to leave Madurai and lead a peaceful life at her uncle's place in the United States by giving her the necessary certificates and money. Muthupandi catches her when she starts fleeing because by coincidence she gets into one of the lorries owned by him. At this juncture, Velu, who is in Madurai to play in a kabaddi tournament, rescues Dhanalakshmi and takes her to Chennai.
Velu takes Dhanalakshmi to his house and hides her in his room, unknown to his family. With the help of his friends, he arranges passport, visa and flight tickets for Dhanalakshmi so that she can go to the U.S. Meanwhile, Muthupandi and his father (Tanikella Bharani), who is the Home Minister, ask Sivasubramanian to search for Dhanalakshmi and the apparent kidnapper. When Sivasubramanian discovers that it is his own son who did the "crime", Velu and Dhanalakshmi run away and hide in the lighthouse. Dhanalakshmi has by now fallen in love with Velu, and has been accepted by Velu's mother and sister. So she is reluctant to go to the U.S. Velu however, is adamant on sending her to the U.S. and he, along with his friends, get her to the airport in time for her flight before their kabaddi match against Punjab in the final of the National League. Sivasubramanian, enraged that his son is a wanted criminal and yet is playing in a kabaddi match, goes to the stadium to arrest Velu. By now, Velu too has fallen in love with Dhanalakshmi and begins to miss her, only to spot her in the stadium during the match. Velu's lack of focus in the game is replaced by his best on seeing Dhanalakshmi, winning Tamil Nadu the championship. After winning the championship, Velu is arrested by his father, but is then stopped by Muthupandi, who wants to fight Velu, having been incited by Dhanalakshmi to do so to prove his worth. Velu defeats Muthupandi and embraces Dhanalakshmi, but when Muthupandi regains consciousness and tries to kill Velu, he accidentally falls on a floodlight and dies.Vijay as SaravanaveluTrisha Krishnan as Dhanalakshmi, as Saravanavelu's love interestPrakash Raj as Muthupandi, a factionalist leaderAshish Vidyarthi as Sivasubramanian, Saravanavelu's fatherTanikella Bharani as Muthupandi's fatherJanaki Sabesh as Saravanavelu's motherBaby Jennifer as Bhuvana, Saravanavelu's younger sisterDhamu as Otteri NariVinod Raj (actor Vikram's father) as Dhanalakshmi's fatherT. K. Kala as Muthupandi's motherNagendra Prasad as PrasadAadukalam Murugadoss as AadhivasiMayilsamy as NarayanaBrahmanandam as a priestAppukutty as priest's assistantPonnambalam as ArivazhaganNandha Saravanan as Saravanavelu's enemy (opposite team leader)Pandu as Police InspectorKarate Raja as Muthupandi's henchmanSaai Sundar as Raghu, Dhanalakshmi's second brotherAmmuVimal as Saravanavelu's team mate (uncredited role)Pandi as road side seller
Vijay expressed interest in starring in a Tamil remake of the Telugu action film Okkadu and prompted producer A. M. Rathnam to purchase the remake rights of the film. Dharani was finalized as the director, whose previous film Dhool under Rathnam's production had been a financial success. Dharani's regular crew members including cinematographer Gopinath and music director Vidyasagar joined the film, while Rocky Rajesh and Raju Sundaram were chosen to choreograph the stunts and dances, respectively. Jyothika and Simran were considered for the role opposite of Vijay, but the former opted out due to date problems and the latter opted out due to her wedding arrangements and other schedule conflicts. Later Trisha Krishnan was confirmed to play the female lead, while Prakash Raj was signed on to reprise the villain's character from the original. Dhamu and Prabhu Deva's brother, Nagendra Prasad were recruited to essay supporting roles. Ashish Vidyarthi, Janaki Sabesh and Baby Jennifer were selected to portray Vijay's parents and sister, respectively. Playback singer T. K. Kala made her acting debut with this film. Vimal who went on to act in films like Pasanga (2009) and Kalavani (2010) appeared in a small role as one of Vijay's teammates and also worked as "unofficial" assistant director.
Filming began in mid-2003, after Vijay had completed his action flick Thirumalai; the film was completed by early 2004. Filming took place in Chennai surrounding the coastal areas like Mylapore and Besant Nagar. The film's introduction fight scene and a song were shot in a costly set in Prasad studios. A lighthouse set was also erected. Other action and chasing sequences were canned near the Meenakshi Amman Temple in Madurai. The climax scene was shot in a crowd of one hundred thousand people on a Vinayagar Chaturthi occasion.
The soundtrack features 6 songs composed by Vidyasagar.The lyrics were penned by Yugabharathi, Pa. Vijay, Na. Muthukumar, Kabilan and Maran. The soundtrack became a sensation on release. The song Appadi Podu in particular enjoyed high popularity upon release, all over South India and became a huge chartbuster. The song was later reused by Chakri as "Adaragottu" in the Telugu movie Krishna (2008). The song was also adapted as Hum Na Tode in the Hindi movie Boss starring Akshay Kumar. Following the internet phenomenon of "Why This Kolaveri Di" in 2011, "Appadi Podu" was featured alongside "Oh Podu", "Nakka Mukka" and "Ringa Ringa" in a small collection of south Indian songs that are considered a "national rage" in India.
Ghilli was due for release on 9 April but later got postponed for a week and opened in over 150 theaters on 16 April. Though the reason for the postponement was not given out, rumors were that producer A M Rathnam's creditors put pressure on him to settle his accounts before release.
Sify appreciated the film for its fast moving screenplay and said as a racy entertainer giving a rating of 3.5/5 stars. Nowrunning.com stated that "Gilli, story wise, is neither fresh popcorn nor spicy samosa found in theaters but the screenplay and overall treatment is as fresh and appetizing as full meals after a long day and gave an overall rating of 3/5 stars. The Hindu stated that "Vijay, the hero whom the masses today identify with, and Prakash Raj, the inimitable villain in tow, this remake of the Telugu flick, "Okkadu," comes a clear winner". Indiaglitz described the film as "an out and out entertainer". Rediff stated that, "Don't miss 'Ghilli'.
Made on a budget of ₹8 crore, Ghilli grossed almost ₹21 crore in India. The film collected ₹2.05 crore in the Coimbatore distribution territory or 85% of Padayappa.Filmfare Award for Best Villain – Tamil – Prakash RajFilmfare Award for Best Dance Choreographer – South – Raju SundaramMadras Corporate Club Best Actor Award – VijayDinakaran Best Actor Award – VijayFilm Today Best Actor Award – VijayDinakaran Best Villain Award – Prakash Raj
The film established Prakash Raj as a villain and the dialogue Chellam became popular. The scene where Vijay threatens to hurt Trisha when Prakash Raj, who allows him to pass through unopposed was included in the list "Top 20 Mass Scenes" by Behindwoods. The scene was parodied by Shah Rukh Khan in Chennai Express (2013). Behindwoods rated Ghilli as "2004's summer blockbuster of the decade (from 2003 to 2013)".