The 30-year-old left-back came up through the youth ranks at Atletico and, either side of two-year loan spell at Osasuna, spent a decade with the Rojiblancos first team before leaving at the end of last season.
During his time with Atletico, Lopez twice won the Europa League (2010 and last season) as well as the 2010 UEFA Super Cup. Lopez has also made 16 appearances for Spain.
A statement on www.rcdmallorca.es read: "Antonio Lopez has reached an agreement with the club to be their first signing of the 2012/13 season.
"The 30-year-old defender will sign for two seasons with the option of another and will be presented this afternoon at 1730 (local time) at the Iberostar stadium."