Tim was born July 20, 1986 in Atlanta, Georgia. He is a professional sailor and America's Cup Grinder and currently lives in Halifax, Canada. He competed with American Magic in the 36th America's Cup.
Prior to his sailing career he was as an American sprint canoeist. At the 2012 Summer Olympics, he competed in the Men's K-1 200 metres.
Hornsby qualified through a long and difficult route. He won the Men’s K1 200m event at the 2011 Sprint National Championships in Gainesville, Georgia. on August 6. However, US teammate Ryan Dolan had achieved the result that gave the US an Olympic canoeing quota slot for the U.S. at the 2011 Pan American Games in Guadalajara, Mexico on October 28.
Hornsby then won the 2012 U.S. Olympic Team Trials in Oklahoma City on April 20, forcing a race-off between the two at the first two 2012 World Cups. Hornsby then achieved a 14th-place finish at the 2012 World Cup No. 2 in Duisburg, Germany on May 27, clinching the US K-1 200 m Olympic place for himself as his result was better than Dolan's.
Hornsby's home club is the Lanier Canoe and Kayak Club. Lake Lanier hosted the canoe, kayak and rowing events at the Atlanta Olympics, but Hornsby is the first Olympian they have produced.