The deal also contains a club option for a sixth year.
"It means a lot that these guys want me to be the face of the franchise, which I'm ready to be," said Maybin, who was selected the team's most valuable player in 2011. "I didn't have the year I wanted to (last year). I think there's a lot more in there and a lot to come."
San Diego acquired Maybin from the Marlins in December 2010 in exchange for relievers Edward Mujica and Ryan Webb. Maybin hit .264 with 40 stolen bases in 137 games as the Padres' center fielder last year.
Maybin would have been eligible for salary arbitration in 2013. His new contract extends through his first year of free agency, and could cover two years of free agency if the Padres exercise their option.
Representatives for Maybin and the Padres' front office have been engaged in contract talks since last September. Maybin recently switched agents and returned to Brian Goldberg, who previously represented Ken Griffey Jr.
"I think the fact he has fan appeal is a nice bonus," Padres GM Josh Byrnes said. "He's a guy who's invested in teammates and winning. He gets high reviews around the club. He's only 24 and he has to earn the next level of status. But his character was important in making this type of investment."
Maybin said the deal does not contain a no-trade clause, but a source told ESPN.com that Maybin had asked for one as a show of commitment from San Diego. The Padres declined because they have a team policy against giving no-trade clauses, the source said.
Maybin's deal marks the first time the Padres have signed one of their own players to a long-term contract since December 2007, when they locked up Jake Peavy. The Padres also signed Adrian Gonzalez and Chris Young to team-friendly deals during the 2007 season.
"It's a great thing that ownership and (Byrnes) got together with Cam and his agent and worked this out," Padres manager Bud Black said. "This gives Cam some security and stability and gives us a player that is under contract that we're excited to have."
Black's coaching staff has been impressed with Maybin's work ethic since he came over in the trade from the Marlins.
Maybin said he was flattered by talk of a potential contract extension, but tried to keep his mind on baseball. Last week, Maybin reported to camp and said he was only focused on the field and not on his contract situation.
"My track record over the last couple of years is you don't believe it until you see it," Maybin said. "But even if it didn't happen they were going to get the same player."
Maybin, 24, has a career .255 batting average with a .318 on-base percentage in parts of five seasons with Detroit, Florida and San Diego. The Tigers selected him with the No. 10 overall pick in 2005, then traded him to Florida in 2007 as part of an eight-player deal that sent Miguel Cabrera and Dontrelle Willis to Detroit.
Jerry Crasnick is a senior baseball writer for ESPN.com. Information from The Associated Press contributed to this report.