[19][21] Trisha had aspired to become a criminal psychologist initially, and resisted the thought of pursuing acting, as she wanted to complete her studies first.

[19] Soon after her pageant success, Trisha began her acting career in a minor supporting role as Simran's friend in the romantic drama Jodi (1999).

[28] The masala flick became the biggest blockbuster of the year,[29] and landed Trisha new offers, including several high-budget productions.

Critics lauded her performance as Sailaja, a middle-class girl who becomes a film star on her father's insistence; Jeevi from Idlebrain stated that she was "beautiful" and a "big plus to the film", labelling her performance as "natural",[34] while Sify noted that she had "transformed herself into a fine actress with immense screen presence".

[35] A critic from fullhyderabad.com praised her, citing that she had shown why Tamil Nadu was "busy building her a temple", further adding that she looked "so fresh and fine, you feel like gifting her to the roses".

She next appeared in a small role in Mani Ratnam's political drama Aayutha Ezhuthu (2004), starring as part of an ensemble cast that included Siddharth, Madhavan and Surya.

The film, being Prabhu Deva's directorial debut, opened to rave reviews, with Trisha receiving praise for her portrayal as the village girl Siri.

[47][48] Continuing her string of releases in 2005, she then starred alongside Mahesh Babu in the action thriller Athadu, which proved to be a critical and commercial success, and her performance as Poori earned her third nomination for the Filmfare Award for Best Actress – Telugu.

Trisha received praise for her performance in her next release, Radhamohan's Abhiyum Naanum (2008) she played the role of Abhi, a independent young woman who has a close-knit bond with her father.

[55][56] The film centres around the complicated relationship between a Syrian Christian Malayali girl and a Tamil Hindu assistant director, who falls in love with her, only to be met by her indifference and reluctance as they belong to different religions and her strict conservative family will never consent to their marriage.

[62] Trisha was part of two commercially successful ventures in 2011, Theenmaar the female lead opposite Pawan Kalyan in Telugu and Venkat Prabhu's Mankatha in Tamil.

[64][65] In 2012, she had two Telugu releases – Bodyguard, a remake of the same-titled Malayalam film, where she was paired with Daggubati Venkatesh for the third time,[66] and Dammu opposite N. T. Rama Rao Jr.

She signed on two "women-centric" bilingual projects featuring female lead casts, titled Rambha Urvasi Menaka[69] and Kannaale Kannan.

[72] Trisha's releases in 2015 included Yennai Arindhaal opposite Ajith Kumar, directed by Gautham Vasudev Menon, she played the role of a bharatanatyam dance teacher and a single mother, raising her young daughter.

In Thoonga Vanam she played the role of an NCB (Narcotics Control Bureau) agent,opposite Kamal Haasan.

[74] In 2016, she starred in the political drama Kodi portrayed ruthless politician with negative shades who is both love interest and political rival alongside Dhanush, which proved to be a critical and commercial success, earning her the Filmfare Critics Award for Best Actress – Tamil, in addition to her fourth nomination for the Filmfare Award for Best Actress – Tamil.

[75][76] Following this, she played a leading role in the Tamil romantic drama '96 opposite Vijay Sethupathi and received widespread critical acclaim.

[84][85] In 2020,she reprised her role as Jessi from Vinnaithaandi Varuvaayaa in the short flim Karthik Dial Seytha Yenn (2020) presenting fresh narrative for the character.

[86] This was followed by her 60th film appearance with a starring role in Paramapadham Vilayattu (2021) a political thriller where Trisha played a key character, and her performance was praised for its intensity.

[87] She was next seen in Mani Ratnam's 2022 film Ponniyin Selvan: I, in the role of the Chola princess, Kundavai, her performance received critical acclaim and she was nominated for Filmfare Award for Best Actress – Tamil.

[91] Her first release of 2023 was the sequel Ponniyin Selvan: II, where she reprised her role as Kundavai,and she was nominated for Filmfare Award for Best Actress – Tamil.

[94] She also made a special appearance in the film The Greatest of All Time, captivating audiences with her performance in the dance number "Matta".

[95] In 2025 action thriller film Identity she played a news presenter and murder witness who suffered from face-blindness after a traumatic event.

[96][97]She played a character in Vidaamuyarchi, where the central theme is marriage, highlighting love, commitment, and the challenges the couple faces together.

[102] Her mother, Uma Krishnan, accompanies Trisha on film shoots, events, and functions, and they have appeared together in a commercial advertisement.

[103] Uma had been offered various roles by several Tamil film makers and actors including Kamal Haasan, but turned them down as she wanted to concentrate on Trisha's career.

[109] In 2010, Trisha collaborated with People for the Ethical Treatment of Animals (PETA) in issuing a public appeal to domesticate stray dogs rather than craving for pedigreed foreign breeds.

[110] She was also the Goodwill Ambassador for the "Angel for Animals" campaign organised by PETA in 2010, encouraging people to adopt homeless dogs.

[115] Filmfare noted, "Trisha has remained popular with audiences by regularly playing endearing characters and appearing in blockbuster films."

[1] Gautam Sunder noted, "She has sustained two decades in films as a leading actor with proven mettle and box-office success."