Tamlyn Tomita made her screen debut in the 1986 John G. Avildsen-directed American martial arts drama film ‘The Karate Kid Part II’ where she portrayed ‘Kumiko.’ The film received mixed reviews from critics but was a financial success and grossed $130 million at the box office. In 1987, she joined the cast of the American television soap opera ‘Santa Barbara’ as ‘Lily Murakami, Ming Li.’ She starred in 31 episodes and remained on the show until 1988. Tomita went on to star in television films and series such as ‘To Heal a Nation’ (1988), ‘The Karate Kid’ (1989), ‘Hiroshima: Out of the Ashes’ (1990), ‘Quantum Leap’ (1992), ‘Babylon 5: The Gathering’ (1993), ‘Vanishing Son II’ (1994), ‘Highlander: The Series’ (1994), ‘Vanishing Son IV’ (1994), ‘Vanishing Son’ (1995), ‘The Burning Zone’ (1996-1997), ‘The Sentinel’ (1997), ‘Chicago Hope’ (1998), ‘Will & Grace’ (1999), ‘Nash Bridges’ (2000), ‘FreakyLinks’ (2001), ‘Crossing Jordan’ (2001), ‘JAG’ (2002-2003), and ‘Threat Matrix’ (2003). In 2004, she portrayed ‘Janet Tokada’ in the American science fiction disaster film ‘The Day After Tomorrow’ directed by Roland Emmerich. The film received mixed reviews from critics but managed to gross over $552.6 million on a budget of $125 million.
She was next seen in television series and shows like ‘Commander in Chief’ (2006), ‘Eureka’ (2006-2007, 2009), ‘Women's Murder Club’ (2007), ‘General Hospital’ (2008-2009), ‘Saving Grace’ (2008), ‘Monk’ (2009), ‘Criminal Minds’ (2009), ‘CSI: Miami’ (2009), and ‘Memphis Beat’ (2010). In 2010, she became a part of the American police procedural and legal drama television series ‘Law & Order: LA’ by Dick Wolf. She played the role of ‘Miwako Nishizawa’ and remained a part of the show until 2011. She continued to star in television series like ‘Days of Our Lives’ (2012), ‘Touch’ (2012), ‘Bones’ (2013), ‘Teen Wolf’ (2014-2015), and ‘Chasing Life’ (2015). She portrayed ‘Heather Cromwell’ in the 2016 American psychological horror film ‘The Good Neighbor’ directed by Kasra Farahani. The film mostly received negative reviews from critics and holds a 33% approval rating on Rotten Tomatoes. She next appeared in television series like ‘The Good Doctor’ (2017-2019), ‘Counterpart’ (2018), ‘The Man in the High Castle’ (2018), ‘Star Trek: Picard’ (2020), and ‘DuckTales’ (2020). She was last seen in the American martial arts comedy-drama television series ‘Cobra Kai’ in 2021.