Kavya Madhavan first appeared as a child actor in Kamal's film Pookkalam Varavayi (1991) at the age of seven. Subsequently, she was offered parts in other projects such as Pavam IA Ivachan (1994), Parassala Pachan Payyannur Paramu (1994) by P.Venu and Azhakiya Ravanan (1996), directed by Kamal.
She was offered the female lead in Chandranudikkunna Dikhil, also starring Dileep, in 1999.
After the success of Chandranudikkunna Dikhil, Kavya Madhavan and Dileep became a popular pairing in Malayalam cinema, and they worked together in 18 movies. Some of their movies are Thenkasipattanam (2000), Darling Darling (2000), Meesa Madhavan (2002) which was one of biggest grosser of the year and was directed by Lal Jose, Mizhi Randilum (2003) in which she played a double role, Sadanandante Samayam (2003), Thilakkam (2003) directed by Jayaraj, Runway (2004) directed by Joshiy, Kochi Rajavu (2005), Lion (2006) again directed by Joshiy, Chakkara Muthu (2006), Inspector Garud (2007), Paappi Appacha (2010), Vellaripravinte Changathi (2011) and Pinneyum (2016). Most of their movies were in the romantic comedy genre.
She also acted in films with Mammootty and Mohanlal, and in movies with several stars, such as Ee Pattanathil Bhootham, Christian Brothers and China Town.
She got critical acclaim for her performance of the role of Ganga in Perumazhakkalam for which she won 2004 Kerala State Film Award for Best Actress and for the role of Ashwati in Gaddama where she played a housemaid working in Saudi Arabia. The movie was based on a feature by K. U. Iqbal, published in Bhashaposhini. The movie was directed by her mentor Kamal, and she got her second Kerala State Film Award for Best Actress for 2011. She won the 2011 Kerala Film Critics Awards for Best Actress, Amrita-FEFKA Film Awards for Best Actress, Best Actress-Malayalam cinema in 59th Filmfare Awards South and Best Actress in Thikkurissy Foundation Awards. She was nominated in National film award for Best Actress but lost out in the final round. She was part of big grossers like Christian Brothers and China Town in 2011 and was selected as Top Star (Female) 2011 in Malayalam.
She was cast in Adoor Gopalakrishnan's Naalu Pennungal in which she played a supporting role.
Though she had many offers from Tamil cinema, she was very reluctant to act due to her busy schedule in Malayalam. Her first was Kasi (2001) which was the remake of Vinayans Vasanthiyum Lakshmiyum Pinne Njaanum. She went on to act in En Mana Vaanil and Sadhu Miranda and enjoyed moderate success.
She wrote lyrics for the song "En Khalbillulloru Pennaanu" for the film One Way Ticket. She sang her first movie song for the Malayalam film Matinee (2012).
Kavya Madhavan married Nishal Chandra on 9 February 2009, after which she moved to Kuwait. However, she returned home in June the same year and filed for divorce on 24 July 2010. Both Kavya and Nishal appeared before the court on 25 May 2011 and expressed their willingness for a mutual divorce. The divorce was granted on 30 May 2011. After long speculations regarding her romantic relationship with Malayalam actor Dileep and despite both denying it on several occasions, she married him on 25 November 2016 at Vedanta Hotel, Kochi. Many famous from tinseltown attended the wedding including Mammootty, Menaka Suresh, Jomol, Srinda, Meera Jasmine, Jayaram.
In April 2013, Mathrubhumi Books published a collection of memoirs written by Kavya, titled Kathayil Alpam Kavyam which gives a glimpse into her childhood memories and the experiences of her school days and in the film industry. The book was released by writers Subhash Chandran and Deedi Damodaran at a function held in K. P. Kesava Menon Hall in Kozhikode on 11 April.
On 25 July 2017, Kavya Madhavan and mother were questioned by a special investigation team from Kerala Police for six hours probing the alleged abduction and rape of a popular south Indian actress. Her husband Dileep was arrested in the molestation case and remanded into judicial custody. The police had previously conducted a raid in Kavya Madhavan's online boutique 'Lakshyah' on suspicion that a memory card, containing the video recording of the molestation. Pulsar Suni, the prime accused in the case told the police that after committing the crime, he had handed over the memory card at 'Laksyah'. Reportedly, Pulsar Suni told the police that he had worked as driver for Kavya Madhavan for two months, but Kavya Madhavan denied the statement. The police decided to interrogate Kavya once again and also question her friends and close relatives regarding the matter."Mounamaay Manassil," Matinee (2012)"En Kalbilulloru," One Way Ticket"Kalaam Neeangu poyo," Akashvani (2016)
In 2012, Kavya released a Malayalam album titled Kavyadalangal which was composed by Twinz Tunes and Kavya. She was featured in the video under the direction of Aneesh Upasana.Kerala State Film Awards2004: Kerala State Film Award for Best Actress – Perumazhakkalam2011: Kerala State Film Award for Best Actress – GaddamaFilmfare Awards South2011:Filmfare Best Malayalam Actress Award – GaddamaAsiavision Awards2013: Best Actress – Best ActressKerala Film Critics Award2000: Second Best Actress – Chandranudikkunna Dikhil2001: Second Best Actress – Kochu Kochu Santhoshangal2003: Second Best Actress – Mizhi Randilum2005: Best Actress – Anandabhadram2010: Best Actress – GaddamaSouth Indian International Movie Awards2013: SIIMA Special Appreciation Award for her contribution to Malayalam Cinema2011: Best Actress – GaddamaAsianet Film Awards2000: Special Jury Award – Kochu Kochu Santhoshangal, Madhuranombarakattu2002: Best Star Pair – Meesa Madhavan2002: Best Actress – Oomappenninu Uriyadappayyan2004: Special Jury Award Actress – Perumazhakkalam2009: Best Actress – Banaras2011: Best Actress – Gaddama, Bhaktha Janangalude Sradhakku2012: Best Actress – Bavuttiyude NamathilVanitha Film Awards2004: Best Actress – Mizhi Randilum2006: Best Actress – Anandabhadram2011: Best Actress – GaddamaMathrubhumi Film Awards2002: Best Popular Actress – Meesa Madhavan2002: Best Star Pair – (Dileep and Kavya)2003: Second Best Actress – Mizhi Randilum2004: Special Jury Award Actress – Perumazhakkalam2007: Best Popular Actress – All Films 20072009: Best Actress – Banaras2011: Best Actress – GaddamaAmrita TV FEFKA Film Awards2010: Best Actress – Gaddama2011: Best Popular Actress – All Films 20112013: Best Actress – Bavuttiyude NamathilKerala Film Audience Awards2001: Monisha Award2003: Best Actress – Oomappenninu UriyadappayyanOther Awards2000: Bharathan Award – Navagatha Prathibha Chandranudikkunna Dikhil2003: Fourth Raju Pilakkad Chalachithra Award – Oomappenninu Uriyadappayyan2007: Sathyan Memorial Award for Best Actress – Nadiya Kollappetta Rathri2011: Sathyan Award2011: Lalitha-Padmini-Ragini Memorial Award2011 Viewers Choice Award for Best Actress – Gaddama2011: Reporter TV Film Award for Best Actress – Gaddama2011: Manappuram Kanyaka Minnale Film Awards for Young Megastar Female2011: Thikkurissy Foundation Film Awards for Best Actress – Gaddama2011: The Kochi Times Film Awards 2011-Best Actor Female for Gaddama2011: Surya TV Film Awards for Best Actress – Gaddama, Bhaktha Janangalude Sradhakku2012: Aimfill – Inspire Film Awards 2011 – Best Actress – Gaddama2013: Mahatma Kala Samskrithi Mahatma Film Awards for Best Actress – Bavuttiyude Namathil2013: Kala Rathnam Award from Nileshwaram Rotary Club.2014: MIR Film Awards "Pride of Malabar" by Kannur Vision & Smartsa Creations