Walter "Bunny" Sigler (born March 27, 1941 in Philadelphia, Pennsylvania) is a pop and R&B songwriter and record producer who has done extensive work with the team of Kenny Gamble and Leon Huff, and who was instrumental in creating the "Philly Sound" in the early 1970s. He is nicknamed "Mr. Emotion."

Sigler has worked with most of the artists associated with the Philadelphia stable including The O'Jays, The Roots, Jackie Moore, Harold Melvin & the Blue Notes, Barbara Mason, Billy Paul, Lou Rawls, Patti LaBelle and Stephanie Mills. He also co-wrote "The Ruler's Back", the opening song on the album The Blueprint by Jay-Z.