Joanna is a leading actress in the West End and on the international stage; as Kim in Miss Saigon

(London, original Australian production, original United Kingdom and Ireland Tour and The 10th Anniversary Performance),

Eponine and Fantine in Les Misérables (London, Belfast and Windsor performed for HM Queen Elizabeth II and the Royal Family), Mary Magdalene in the West End revival of Jesus Christ Superstar (London), Mimi in Rent (European Tour), Christmas Eve in Avenue Q (London), Sheila Franklin in Hair (London), Thanh in the world premiere of The Real Love (Los Angeles), Heidi in I Sing! (London), The ingénue June in The Musical of Musicals (London), Francesca Johnson in the international premiere of The Bridges of Madison County (Manila), Inang Bayan in Rebel EDSA 30 (Manila), Maria in West Side Story (Manila), Maria Von Trapp in The Sound of Music (Manila), Nellie Forbush in South Pacific in Concert (Manila), Blue Fairy in Pinocchio: A New Musical (Singapore), West End Women (UK Tour), The Magic of Disney in Concert (Hyde Park, London), Defying Gravity: The Songs of Stephen Schwartz (Sydney), Grizabella in Cats (UK & European Tour 2013-14, World Tour 2017-2018, Asian Tour 2019-2020), Mary Magdalene in the Tokyu Theatre Orb's production of Jesus Christ Superstar (Tokyo) and Jenna in the international premiere of Waitress (Manila).

She can be heard on the cast recordings of Miss Saigon: Complete Symphonic Recording as Kim, Jesus Christ Superstar: 1996 London Cast as Mary Magdalene, The Postman and the Poet as Beatriz Gonzalez and the soundtrack of the feature film Ang Larawan as Candida. Her debut album Joanna Ampil was recorded in Abbey Road Studios in 2007 by JAY Records, followed by Try Love in 2010 by Sony Music and Joanna Ampil in 2014 with VIVA Records. Her latest singles  are Always Better and Memory.

She portrayed Candida in the feature film Ang Larawan (The Portrait) where she won the Metro Manila Film Festival MMFF 2017, PMPC Star Awards, Gawad Pasado, Luna, Gawad Tangi, Guillermo Award, Urduja Best Heritage Film Awards and the prestigious Gawad Urian Best Actress Awards.

She can be seen in the digital and television series "Babae Sa Septic Tank 3" (iWant TV), "Call Me Tita" (iWant TV, ABS CBN, TFC) and "Broken News" (BBC).  She portrayed Corazon in Maalaala Mo Kaya's "Kadena" (ABS-CBN, iWant TV)  wherein she won the GEMS Award for Best Actress for Television.

She will soon reprise Grizabella in the 40th Anniversary Tour of Cats (Autumn 2020/2021) in South Korea. 

and portray Bloody Mary in the Chichester Festival Theatre's South Pacific (Summer 2021) in United Kingdom.