Facundo Bagnis (Spanish pronunciation: [faˈkundo ˈβaɣnis]; born 27 February 1990) is an Argentine professional tennis player. He has a career-high singles ranking of World No. 55 reached in November 2016. Bagnis competes mainly on the ATP Challenger Tour where he has won 17 singles titles. He also won one ATP doubles title in Stuttgart. Bagnis was given a provisional ban from tennis in October 2025 after failing an anti-doping test.