The signing came Friday, when the Cowboys opened a minicamp that will be their last organized team workouts until training camp opens in six weeks.
Cowboys owner Jerry Jones has said the Cowboys want to sign Austin to a long-term deal.
Austin went from relative unknown to Pro Bowl pick last season, when he caught 81 passes for 1,320 yards and 11 touchdowns. He broke Bob Hayes' single-game Cowboys record with 250 receiving yards against Kansas City in October, when he caught 10 passes and had two touchdowns.
Had Austin not signed his tender by Tuesday, the Cowboys could have reduced it to $1.65 million, or 10 percent over his 2009 salary.