He will receive $1.4 million, according to a major league source.
"We've had the great fortune to get to know Matt the last seven-plus months and are excited by his decision to devote himself completely to baseball and the Cubs," Cubs general manager Jim Hendry said in a statement. "We've come to know Matt not only as a talented athlete but also as an exceptional person. He had a fantastic pro debut with us last summer and we look forward to supporting and fostering his continued development as a baseball player."
Szczur, a 5-foot-11, 205-pound outfielder, received a $100,000 bonus from the Cubs when he originally signed with the team in June. The Cubs gave him permission to return to Villanova for his senior year, but he missed much of the season with a high ankle sprain.
He played for three different minor league teams in the Cubs system, and began his professional career with a 21-game hitting streak.
"It was just, what was a better option for me," Szczur said Thursday at Villanova. "I love both sports. If I chose football, it would have been hard to walk away from baseball. It's hard to walk away from football, as well."
Szczur is a center fielder by trade and bats right-handed. He's considered exceptionally fast, and he projects as one of the fastest players in the Cubs organization.
He hit .347 in 25 minor league games.
"That's what was so good about the minor leagues," he said. "All I had to do was focus on one thing. I had such a good season and it was great being there. A big part of me playing so well was that I was focused."
An MLB source said Szczur will start the season in Single A Peoria in 2011.
The signing was first reported by Baseball America.
Bruce Levine covers the Cubs for ESPNChicago.com. Information from The Associated Press was used in this report.