Madhavan began his acting career with television guest appearances, including a role on the Zee TV prime-time soap opera Banegi Apni Baat in 1996. After appearing in commercials and in small roles, he later gained recognition in the Tamil film industry through Mani Ratnam's successful romance film Alaipayuthey (2000). Madhavan soon developed an image as a romantic hero with notable roles in two of 2001's highest grossing Tamil films, Gautham Menon's directorial debut Minnale and Madras Talkies' Dumm Dumm Dumm. He worked with Mani Ratnam again in the critically acclaimed 2002 film Kannathil Muthamittal playing the father of an adopted girl, whilst he achieved commercial success with his role in N. Linguswamy's action film, Run (2002). Madhavan was cast alongside Kamal Haasan in the 2003 drama Anbe Sivam, which earned him two notable awards for Best Supporting Actor. In 2004, he gave a critically acclaimed performance as the antagonist in the multi-starrer Aayutha Ezhuthu and the film secured him his first Filmfare Award for the intense portrayal of a rogue.
In the mid-2000s, Madhavan also actively pursued a career in Hindi films, by appearing in supporting roles in three highly successful productions, Rakeysh Omprakash Mehra's Rang De Basanti (2006), Mani Ratnam's biopic Guru (2007) and Rajkumar Hirani's 3 Idiots (2009), which went on to become the highest grossing Indian film of all time upon release. He simultaneously worked on Tamil films, gaining critical acclaim for his portrayal of a vigilante in his home production Evano Oruvan (2007) and for the successful bilingual horror film, Yavarum Nalam (2009). After appearing in further box office hits, Tanu Weds Manu (2011) and Vettai (2012), Madhavan took a break from acting. Returning after a three-year sabbatical in 2015, his comeback films, the romantic-comedy Tanu Weds Manu Returns (2015), the bilingual sports drama Irudhi Suttru (2016) and the crime film Vikram Vedha (2017) all won critical and commercial acclaim. His performance as a boorish boxing coach in Irudhi Suttru fetched him Best Actor awards at the Filmfare, IIFA and SIIMA award ceremonies.
In addition to his acting career, Madhavan has worked as a writer on his films, hosted television programmes and has been a prominent celebrity endorser for brands and products. He has also worked as a film producer, first making Evano Oruvan with Leukos Films, before setting up Tricolour Films to produce Saala Khadoos (2016). Madhavan is noted for his philanthropic activities and promotes various causes such as environment, health and education. He is particularly vocal about the protection of animals and was awarded PETA's Person of the Year recognition in 2011.
Madhavan was born on 1 June 1970 in Jamshedpur, Bihar (now in Jharkhand), India, into a Tamil Iyengar family. His father Ranganathan was a management executive in Tata Steel and his mother, Saroja was a manager in the Bank of India. His younger sister, Devika, is a software engineer. He had a Tamil-speaking upbringing in Bihar.
In 1988, Madhavan gained a scholarship to represent India as a cultural ambassador from Rajaram College, Kolhapur and spent a year in Stettler, Alberta, Canada as part of an exchange programme with Rotary International. He returned to Kolhapur and completed his education, graduating with a degree in electronics. During his college years, Madhavan became actively involved in extra-curricular military training and at 22, he was recognised as amongst the leading NCC cadets in Maharashtra, which allowed him to make a trip with seven others as NCC cadets to England. As a result of this opportunity, he received training with the British Army, the Royal Navy and the Royal Air Force, which he had, at a point, considered joining. However he missed the age cut-off by six months and was subsequently unable to join the programme. After he lost out on the place, he began teaching courses on public speaking and personality development skills in Kolhapur and the satisfaction he gained through teaching, prompted him to pursue a post-graduation in public speaking at Kishinchand Chellaram College in Mumbai. During the period, he also won the Indian Championship for Public Speaking and subsequently represented India at the Young Businessmen Conference in Tokyo, Japan in 1992. During his stint in Mumbai, he opted to create a portfolio and submit it to a modelling agency.