Financial terms of the four-year contract were not released.
Miranda, a 23-year-old left-handed hitter, hit .303 with 27 home runs while playing for Cuba from 2002-04. He defected to the Dominican Republic in 2004 and was granted citizenship there in 2005.
"Juan Miranda has impressed our scouts with his talent and strength," Yankees' Dominican Republic Scouting Supervisor Ramon Valdivia said. "He is capable of playing the outfield and first base but his biggest asset is his bat. He has the ability to hit for power while showing excellent plate discipline. We're excited to see what he can contribute to the future of this ball club."
Miranda, Andy Phillips and Josh Phelps are expected to compete for playing time at first base for the Yankees next season as Jason Giambi is likely to be used much of the season as a designated hitter.