Soler, 20, will report to the Cubs' facility in Mesa, Ariz., to begin his Spring Training, general manager Jed Hoyer said Saturday in announcing the deal, which was finalized late Friday.
"He has a ton of power potential for us," Hoyer said. "We scouted him heavily. Obviously, it's a significant commitment for us, but we feel he fits very well into what we want to do -- he's the right age, right talent. We're excited to finally get him started."
A right-handed hitter with power, Soler is considered the next big Cuban prospect on the scene after outfielder Yoenis Cespedes, who signed with the Athletics for $36 million over four years.
Soler had to sign with a Major League club before Tuesday's deadline or be subjected to new Basic Agreement guidelines, which will limit spending on international prospects to $2.9 million per team without penalty.
The holdup was related more to Soler needing to establish residency. He defected from Cuba last year.
Cubs manager Dale Sveum has watched Soler on video, and likes what he has seen.
"The body type and everything like that is like Glenn Braggs," Sveum said Saturday. "You see [Soler's] body and the size and strength, that kind of strength at a young age is pretty impressive. Hopefully it all translates into a huge productive player at this level."
Hoyer and Theo Epstein, Cubs president of baseball operations, watched Soler work out in the Dominican Republic in the offseason. How long will it take the newest Cubs outfielder to get to the big leagues?
"Let's get him in games first," Hoyer said. "He's 20 years old, and we're really impressed with the looks he got in games."
Soler has been in the Dominican Republic, playing in games, but Hoyer said scouting the Cuban has been different than what a team does for high school or college player in the U.S.
"He has huge power," Hoyer said. "It's hard to find power in today's game and that's a big part of why we're willing to make that commitment."
Soler played in the 16 and under COPABE Pan American Championships in Mexico in 2008 and the World Junior Championships in Thunder Bay, Ontario, Canada in 2010. In 2010, he batted .304 with a .500 on-base percentage and .522 sliugging percentage in seven games, and helped Cuba win the bronze medal.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter@CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.