David Franklin Kennedy (May 31, 1939 – October 10, 2021) was an American advertising executive who co-founded Wieden+Kennedy (W+K). Some of his most popular campaigns included the "Just Do It", "Bo Knows", and the "Mars and Mike" campaigns for Nike, Inc. He and his creative partner Dan Wieden were listed as number 22 on the Advertising Age 100 ad people of the 20th century.