William L. Cobb (1917 – December 17, 1990) was an American designer and engineer of roller coasters, as the founder and head of William Cobb & Associates. He is particularly noted for his work on designing and relocating several major wooden roller coasters in the 1970s and 1980s. A number of these coasters were world-record holders at the time of their opening. On the subject of roller coaster design, Cobb has been quoted as saying, "You have to be a little bit mean. Sometimes you have to be a little bit sneaky. You get them going on a nice straight track and they think 'This looks smooth,' and then you dip it down a little to give them a good jolt. Or you have it so that when they go over a hill it looks like they're going to get their heads chopped off at the bottom."

List of roller coasters

William Cobb designed 11 roller coasters around the world.