Fonseka started her acting career with stage dramas with
Noratha Ratha produced by H. V. Weerasiri in 1963. In 1968, Fonseka won a national award for Best Stage Drama Actress for her performance in
Akal Wessa produced by Dharmadasa Jayaweera. From 1963 to 1969, Fonseka played the lead role in 14 stage dramas including; B. Ratnayake's
Amal Biso, Sam Perera's
Iwa Bawa Nathi Lowa, S. Karunaratne's
Guththila,
Erabudu Mal Pottu Pipila,
Hiru Awarata Giyado, Sunanda Mahendra's
Sayuren Aa Landa, Prema Kumara Epitawela's
Nuwana Podiya,
Sathischandra Edirisinghe's
Baka Thapas, Sumana Aloka Bandara's
Nidhi Kumba, and
Gunasena Galappatty's
Liyathambara. At the age of 18, she made her film debut with Tissa Liyansuriya's
Punchi Baba (Little Baby) in 1968 with the role "Maali", where she won the Swarna Sankha Award for Best Supporting Actress. The she acted in the films
Abudasse kale,
Dahasak Sithuwili and
Adarawanthayo in the same year. The success of these movies led her to be cast as the lead role by several movie directors of the time. Fonseka acted in over 140 movies thereafter, some of which were international movies. She paired up with popular
Indian Tamil actor,
Sivaji Ganeshan in
Pilot Premnath in 1978. Her career was enhanced by her work alongside
Gamini Fonseka who had a long journey in the history of the silver screen in Sri Lanka. At his funeral in 2004, Fonseka stated "His performance had appeal across the board and I had the good fortune of being associated with Gamini. The cinema of that era is slowly fading away and the passing away of Gamini is another step towards that direction". Her popularity peaked in the 1970s and 1980s, as she collaborated with renowned directors, including
Lester James Peries and
Dharmasena Pathiraja. She successfully made her mark in both Imitative popular cinema (with the films:
Mē Dǣsa Kumaṭada (1972),
Suhada Pæthuma (1973)
Sangeethā (1975) and
Næwatha Hamuvemu (1982) as well as Cinematic popular cinema (with the films:
Dæn Mathakada (1970)
Hathara Denāma Sūrayō (1971),
Edath Sūrayā Adath Sūrayā (1972),
Adarē Hithenava Dækkama (1972) and
Thuṣhārā (1973) at the same time. In the meantime, she became a trendsetter by fashion designs (Mini Frocks, Bell Bottoms, Swimming kit, Cabare kits) and hair cuts for the fans island wide. Her notable performances in the teledramas came through
Manalada Puthe Kiri Dunne,
Pitagamkarayo,
Kemmura,
Ambu Daruwo,
Pin Mada Puthunē,
Mahamera Pāmula,
Mahagiridamba,
Maha Naḍuva and
Depæthi Dahara. She later won the
Sumathi Best Teledrama Actress Awards for her roles in
Pitagamkarayo and
Kemmura. She further solidified her mark as a teledrama director with successful creations such as
Sanasili Suwanda. ==Awards==