"Leonardo Jardim will coach the senior team next season, with a contract valid until June 2015," Sporting wrote in a communication to market regulator CMVM.
The 38-year-old Jardim, who unexpectedly parted company with Greek club Olympiacos in January even though they were leading the league at the time, replaces Jesualdo Ferreira, who failed to secure the target of a Europa League spot for the Lisbon club.
Sporting finished seventh in the championship with 10 defeats and nine draws, in one of their worst seasons.
Before his spell in Greece, Jardim led Braga to third place in the 2011-2012 season.
Sporting are considered one of Portugal's big three clubs, along with Porto and Benfica, but have run into financial trouble and been forced to sell several key players, including top Dutch striker Ricky van Wolfswinkel who went to Norwich.