Mark Adam Hensby (born 29 June 1972) is an Australian professional golfer.
Hensby was born in Melbourne, Victoria. He grew up in Tamworth, New South Wales and attended Tamworth High School, leaving at the age of 16 to work as a postie while spending most of his time on the golf course. He moved to the United States in 1994, and having initially stayed with family friends, for a time slept in his car parked at the Cog Hill Golf & Country Club near Chicago, Illinois. He won the Illinois State Amateur Championship in 1994 before turning professional the following year. He now lives in Mesa, Arizona.
Hensby played on what is now the Nationwide Tour (formerly the Nike Tour and Buy.com Tour) for several years from 1997 before he graduated to the the PGA Tour for the 2001 season. He gained his place on the elite tour by virtue of his 2nd place finish on the Buy.com Tour money list in 2000. In his rookie season, Hensby did not earn enough money to retain his card and was forced to return to the second tier for 2002, after failing to regain his place at the end of season qualifying school. In 2003, he picked up his third win on the Nationwide Tour and finished 7th on the money list, to graduate directly to the PGA Tour for the second time.