Cosgrove topped the Glamorgan averages at 60 in 2009
Australian opening-batsman Mark Cosgrove will return to Glamorgan as their overseas player for 2010.
The left-handed Australia one-day international, 25, topped the county's batting averages this season.
Cosgrove struck three centuries, his seasonal aggregate of 780 runs from 15 innings yielding an average of 60.
"He can play well, score runs quickly and do a great deal of damage to the opposition in a short period of time," said Glamorgan chairman Paul Russell.
Russell was initially seeking a certificate of non-objection from Cosgrove's state, South Australia, before confirming the deal.
But his capture was announced at Glamorgan's end-of-season dinner on Monday, where captain Jamie Dalrymple was named Player of the Year and One-day Player of the Year.
Robert Croft is Glamorgan's first-class Player of the Year, with James Harris winning the young player gong.
Glamorgan's former England all-rounder Alex Wharf said he is to become a professional umpire after his retirement because of injury.
Russell was keen to pay tribute to the qualities that Cosgrove can offer Glamorgan.
"He is not the physical model that one expects of an international cricketer, but we've managed to overcome that," Russell told BBC Sport Wales.
"He's an enormously talented young man, very motivated and committed, and he brings a dimension of pragmatism and good humour to the dressing room.
"Most importantly, he likes Glamorgan, likes what we're trying to achieve here and the set up."
Cosgrove, a British passport holder classed as an overseas player because of his Australia caps, averaged 50 in his previous Glamorgan stint in 2006.
His three Australia one-day games came in 2006, but weight and fitness problems hindered his career down under.