Caroline Pettinato Killeen (born 1926) is an American activist, perennial political candidate, self-proclaimed nature lobbyist, and former nun. She ran as a United States presidential candidate and officially qualified for the ballot in the New Hampshire primary in 2008 as a Democrat; she previously ran in 2004, 1996, 1992 and 1976. She ran on a pro-marijuana platform and is an advocate for energy conservation. Killeen has also run for various offices in Arizona. She ran for Mayor of Tucson in 1983, receiving 11 votes.
Killeen has biked across the U.S. several times to raise awareness of environmental and anti-nuclear issues. She has also advocated drug legalization.