Martin & Regine: The World Concert Tour was a co-headlining tour by Filipino performers Martin Nievera and Regine Velasquez. It began on March 8, 2003 in Honolulu, Hawaii and visited the United States and the Philippines. The joint tour came after the two had finished their own concert residencies at the Onstage Theatre in 2002 — Nievera's Opening Night and Velasquez's Songbird Sings. The tour was announced early in 2003 and was exclusively promoted by Maximedia International. The set list featured songs taken from both singers' discographies, including collaborations such as "You Are My Song" and "Forever", as well as various covers. Louie Ocampo and Gerard Salonga served as the musical directors for the United States and Philippine legs, respectively. Reviews for the tour were generally positive, with critics praising both artists' vocal abilities.

Regina Encarnacion Ansong Velasquez is a Filipino singer and actress. She is considered one of the most influential figures in Philippine popular culture and is known for her vocal range and belting technique. She had unorthodox voice training during her childhood, where she was immersed neck-deep in the sea. Velasquez rose to prominence after winning the television talent show Ang Bagong Kampeon in 1984 and the Asia Pacific Singing Contest in 1989. Under the name Chona, she signed a recording contract with OctoArts International in 1986 and released the single "Love Me Again", which was commercially unsuccessful. The following year, she adopted the stage name Regine Velasquez for her debut studio album, Regine (1987), under the guidance of Viva Records executive Vic del Rosario and producer Ronnie Henares. She explored Manila sound and kundiman genres on her second and third studio albums, Nineteen 90 (1990) and Tagala Talaga (1991).