Tomás Lavanini (born 22 January 1993) is an Argentine professional rugby union player who plays as a lock for Top 14 club Clermont and the Argentina national team.

[7] Lavanini made his senior debut for Los Pumas against Uruguay in April 2013 and was subsequently called into the squad for the 2013 Rugby Championship as injury cover for Manuel Carizza[8] where he made his championship debut as a 74th-minute substitute in his side's 17-22 defeat to South Africa on 24 August.

[citation needed] Lavanini was red-carded in the second test against South Africa in the 2017 Rugby Championship, following two yellow cards being issued to him.

Lavanini made his return from suspension at home against New Zealand in Buenos Aires only to be yellow-carded for a dangerous tackle.

[citation needed] He was red-carded for a high tackle on Owen Farrell in the pool game against England in the 2019 Rugby World Cup for which he received a four match ban.