Mariano Delfino (born 30 September 1977) is a former professional tennis player from Argentina.

[1] Delfino was a qualifier in the 2003 French Open and played against Jean-Rene Lisnard in the first round.

[2] He lost the match in four sets.

[2] His only other appearance on the ATP Tour was in the 2003 Campionati Internazionali di Sicilia, where he and partner Sergio Roitman were doubles wildcard entrants.

[2] They won their opening round match over Austrians Julian Knowle and Jürgen Melzer, but lost in the second round to Christophe Rochus and Tom Vanhoudt.