The 32-year-old becomes the third free-agent pickup by the Marlins over the past week.
"Knowing Mike Redmond was the manager, and looking at the team, knowing that the team has unbelievable talent that can blossom into superstars -- it just seemed like a great fit," Jones said. "Being a team that is developing before everyone's eyes, to be a part of that is something special. It was kind of like that when I was with Pittsburgh. We developed into a winner, and to see the city ignite and erupt -- it's something special to be a part of."
Last Friday, the club announced the signing of catcher Jarrod Saltalamacchia to a three-year deal. Later in the afternoon, it became official that infielder Rafael Furcal, who will play second base, finalized a one-year contract.
"At the beginning of our offseason, our goal was to upgrade our offense," president of baseball operations Michael Hill said. "In Jones, we feel like we've added a consistent, productive bat to our ballclub."
Jones' arrival now means the Marlins are positioned to use incumbent first baseman Logan Morrison as a trade chip. There has been extensive interest in Morrison during the Winter Meetings at the Walt Disney World Swan and Dolphin Resort.
Actually, the Marlins have had measured interest in Morrison since at least the General Managers Meetings last month in Orlando. The Brewers, Rays, Blue Jays, Braves and Orioles are among more than 10 teams who have been in contact with Miami regarding Morrison.
As rumors swirl about Morrison, Hill is playing his cards close to the vest. He noted the Marlins are under no urgency to deal the 26-year-old first baseman any time soon.
Morrison is entering his first season of arbitration.
"He's still affordable," Hill said. "He still has three years of control."
Jones, a left-handed-hitting power threat, has played in at least 144 games in each of the past four seasons.
With Miami, Jones may find himself in more than just a platoon situation, like he was in Pittsburgh. Utility infielder Ed Lucas is a right-handed-hitting first-base alternative to face lefties. And the club is continuing to seek more options.
Throughout his career, Jones has struggled against left-handed pitching. He hit .095 (2-for-21) against them in '13, and he is .193 lifetime.
In 2013, Jones batted .233 with 15 home runs, 26 doubles and 51 RBIs in 440 plate appearances.
"We obviously know about his splits," Hill said. "I know, in a platoon situation, where he doesn't get 500 at-bats, he's struggled more in being consistent. But in years when he's been able to get more than 500 at-bats, we feel like the splits are a little more even."
News broke on Friday that the Marlins were closing in on their ageement with Jones, who was designated for assignment by the Pirates on Nov. 25, clearing the path for him to become a free agent.
Although Jones' home run total was down from the 27 he belted in 2012, reaching as many as 15 was no small achievement in '13. Only 48 players in the National League, and 98 total in the Majors, hit as many as 15. The Marlins had just two players in double figures -- Giancarlo Stanton (24) and Justin Ruggiano (18).
Three times in his career, Jones has connected on 20 or more home runs.
Since his rookie season of 2009, Jones has 100 homers, the 22nd most of any active player in that span. He has 102 career shots, including the two he hit in 31 games when he broke into the big leagues with the Twins in 2007.
Jones also adds some versatility. The 6-foot-4, 230-pounder appeared in 32 games in right field last year.
The Marlins have Stanton as their regular right fielder, and he is not available on the trade front. But having Jones on the roster adds some depth to the outfield.
"Our plan is to play him at first base, but we do know he can, and he has played the outfield," Hill said. "Our plan is for him to be our primary first baseman and be a consistent force in our lineup."