The 44-year-old, from North Berwick, has a net worth of £7 million, with her earnings soaring from endorsements with Aberdeen Asset Management and golfing company Titleist.
Mrs Matthew, who won the British Open 11 weeks after giving birth to her second child, plays on the US LPGA tour.
She sits just behind fellow golfer Laura Davies on The Times' Daily Rich List and is ahead of athlete Jessica Ennis-Hill, golfer Trish Johnson and cyclist Victoria Pendleton - but her earnings are well below golfer Rory McIlory, who is worth £28m.
Mrs Matthew, whose hus-band Graeme is her caddie, signed with sports management company IMG after her win at the British Open at Royal Lytham in 2009.
Victory in the event led to her reputation as the sport's "supermum".