The 20-year-old Matera arrives at Leicester as an injury replacement for Tom Croft who had knee surgery following the opening game of the season.
He goes straight into the squad for Sunday’s Aviva Premiership Round 6 fixture away to London Wasps, taking his place among the replacements.
Tigers director of rugby Richard Cockerill said: “Pablo was very keen to come to us and we’re very happy to have him. As a 20-year-old he wants to come to a place where he can play and develop, and he will be able to do that here.
“He has great raw ability, he was outstanding in the World Under-20s Championships and has now mixed well in very good company in the Rugby Championship with Argentina.”
Matera previously played his club rugby in Argentina with Alumni and made his Test debut in May this year before playing in this season’s Rugby Championship, playing against Australia, South Africa and New Zealand.
He joins fellow Argentina internationals Marcos Ayerza and Gonzalo Camacho at Welford Road.
Click here for all the team news ahead of Wasps versus Tigers.