The 46-year-old posted a closing 69 for a two-stroke victory over Australian Scott Strange who also secured his place on Scotland???s east coast.
Teshima and Strange had been tied for the lead through 54 holes before the former pulled away to secure his eighth title on the Japan Tour.
Teshima said: ???It has been 13 years since I last played in The Open. The Old Course at St Andrews is really very special, it has such a great history and I am really looking forward to playing there in July.???
Strange, meanwhile, will be making his second start in The Open ??? his first appearance came at Royal Birkdale in 2008.
Two other Japanese pros, Shinji Tomimura and Tadahiro Takayama, also qualified for The Open by finishing in a tie for third ??? four strokes adrift of winner Teshima.
Tomimura will make his Open debut, after closing with a brace of 67s, while Takayama will return to the Old Course where he enjoyed a top-25 finish 10 years ago.