Dexter Gilman Wansel (born August 22, 1950) is an American keyboardist, raised in Philadelphia, Pennsylvania. He contributed to the development of the Philly Sound and worked with producers Gamble and Huff at Philadelphia International Records. Wansel led the musical group Yellow Sunshine. He has worked with Phyllis Hyman, The Jacksons, MFSB, Teddy Pendergrass, Patti Labelle, The Jones Girls, Evelyn "Champagne" King, Grover Washington Jr. and Lou Rawls, among many others. He also wrote The Jones Girls 1981 soul music song "Nights over Egypt" and Patti Labelle's 1983 #1 R&B hit, "If Only You Knew", with Cynthia Biggs. His "Theme from the Planets" has been sampled and was featured on the breakbeat compilation album, Ultimate Breaks and Beats.

His most successful album was Life On Mars, released on the Philadelphia International record label in 1976. Wansel played keyboards, Derek Graves played bass guitar while a session singer, Terri Wells, was on vocals. The remaining sound was filled in by Dexter's rhythm section called The Planets featuring Darryl Brown, Calvin Harris, Bobby Malach, Al Harrison and the aforementioned Graves.

Wansel has produced and recorded many soul ballads including the Time is Slipping Away title track, "New Beginning" on that same album, "The Sweetest Pain" (which was sampled by The Solid Doctor for his trip hop track "Lights On The Vibe", by DJ Cam for his track "Dieu Reconnaîtra Les Siens", and by Global Communication for their track "The Way") and "You Can Be What You Wanna Be" from 1976. Wansel also co-wrote and produced the Pieces of a Dream track, "Warm Weather". The track "Rings of saturn" was sampled by Dela for his track "Long Life" featuring Talib Kweli. Purists consider his "I'm In Love Once Again", released on Philadelphia International Records by Jean Carn in 1976, to be his finest work, combining sublime chord sequences with a lavish production.

His song "The Sweetest Pain" was also remade by British R&B group Loose Ends, on their album A Little Spice.