The Marlins made the announcement Tuesday night.
Suzuki signed the deal in his native Japan. A news conference will be held there for him Thursday, with five Marlins executives present, including president David Samson, president of baseball operations Michael Hill and general manager Dan Jennings.
The 41-year-old Suzuki, a 10-time All-Star and 10-time Gold Glove winner, is expected to be the team's fourth outfielder behind Giancarlo Stanton, Christian Yelich and Marcell Ozuna.
"We are thrilled to have Ichiro Suzuki in a Marlins uniform," Marlins owner Jeffrey Loria said in a statement. "He is the ultimate professional on and off the field, and will make an excellent addition to our ballclub."
Suzuki is the first Japanese player to sign with the Marlins. He hit .284 and stole 15 bases for the New York Yankees last season.
Suzuki is a career .317 hitter in the majors and a two-time AL batting champion. The former AL MVP has 2,844 career hits.