Jillian Grace Harper (born December 20, 1985) is an American model. She was Playboy's Playmate of the Month for March 2005. She landed her gig with Playboy after appearing on The Howard Stern Show and posing for test shots, taken by members of the Stern crew. This occurred soon after graduating high school in the town she grew up in, Washington, Missouri.

She had a memorable presence on the Howard Stern show in 2004 and 2005 (as a topic of conversation and in her appearances/call-ins) largely surrounding the crews correct predictions of their perceived "corruption" of her and her stereotypical fall-from-innocence. This included, most laugh-inducingly, that she had had a series of sexual interludes with comedian Pauly Shore. She also mentioned more in passing that she previously dated 7th Heaven actor David Gallagher for several months during one of her later interviews.