Claudine Margaret Castelo Barretto (Tagalog: [klaʊˈdin baˈrɛto]; born July 20, 1979) is a Filipino actress, who made her screen debut on the youth-oriented variety show, Ang TV.

That same year she starred in films like Home Along Da Riles 2 with Dolphy, Calvento Files: The Movie with Rio Locsin and Diether Ocampo, and F.L.A.M.E.S.

Later in 1999, with the debut of the soap opera Saan Ka Man Naroroon where she portrayed as triplets in the name of Rosario, Rosenda and Rosemarie which earned her a nomination for Best Actress in the Asian TV Awards.

In 2001, she was cast as the lead role in the drama series Sa Dulo ng Walang Hanggan (2001–2003) with Carlos Agassi, Luis Alandy, and Mylene Dizon and film Oops!

In 2003, she was joined by Diether Ocampo, Onemig Bondoc, Assunta De Rossi, and Piolo Pascual in the Wenn V. Deramas' series Buttercup (2003–2004).

In 2004, she portrayed a mermaid in the breakthrough fantasy television series Marina with Rafael Rosell Meryll Soriano, Agot Isidro, Snooky Serna, Malou de Guzman and Cherie Gil.

The film received widespread critical acclaim for its original story and cinematography and has been noted as one of the best romance movies of Philippine Cinema.

In 2008, she was cast in Sineserye Presents: Maligno, an extremely violent dark gothic-supernatural thriller television anthology co-starring Kim Chiu, Rafael Rosell and Diether Ocampo.

Also that same year, she landed a remarkable role in the television drama series Iisa Pa Lamang together with Angelica Panganiban, Diether Ocampo, Gabby Concepcion, Cherry Pie Picache, and Susan Roces.

In March 2002, a month after the box-office success of their movie Got 2 Believe, Barretto's on-screen and real-life partner of four years, Rico Yan, died of acute hemorrhagic pancreatitis.

[8] Estoisa-Koo and Anarcon of Pep PH also made a list of "10 Famous Lines from Filipino Teleseryes" where her confrontation scene with Angelica Panganiban landed a spot from the 2008 hit series, Iisa Pa Lamang.

Barretto was awarded Box Office Queen by Guillermo Mendoza Memorial Scholarship Foundation in 2003 and 2006 for the commercial success of her movies, Got 2 Believe and Sukob.

In 2009, she was recognised as one of Cinema One's 15 Legends, together with 14 other iconic film stars of the Philippines who helped define Philippine Cinema which includes Fernando Poe Jr., Dolphy, Nora Aunor, Susan Roces, Nida Blanca, Christopher de Leon, Vilma Santos, Maricel Soriano, Aga Muhlach, Robin Padilla, Judy Ann Santos, John Lloyd Cruz, Sharon Cuneta, and Piolo Pascual.