McGowan was born in Basildon, Essex, and grew up in Banstead, Surrey and educated at Epsom College.

[2] McGowan led the 2007 Challenge Tour Rankings going into the Apulia San Domenico Grand Final, thanks to two wins and three runner-up finishes during the year.

[2] He moved into the top 100 of the Official World Golf Rankings in January of that year, and in June played in his first major championship, the U.S. Open at Torrey Pines.

McGowan won his first European Tour event in 2009 at the Madrid Masters, most notably for shooting 12 under par 60 in the third round.

He showed a return to form in 2015, winning for the first time on the Sunshine Tour in April at the Mopani/Redpath Zambia Open, finishing two strokes ahead South African golfer Daniel van Tonder.