| ITF - Antalya M15 | 01/29 15:15 | 27 | [411] Giovanni Fonio v Corentin Denolly [450] | 6-7,2-6 | |
| ITF - Antalya M15 | 01/29 11:30 | 26 | Giovanni Fonio v S Mert Ozdemir | 6-2,6-2 | |
| ITF - Antalya M15 | 01/28 09:00 | 25 | Giovanni Fonio v Juan P Canas Garcia | 7-5,6-2 | |
| ITF - Antalya M15 | 01/23 08:50 | 29 | [479] Cezar Cretu v Giovanni Fonio [411] | 1-6,4-6 | |
| ITF - Antalya M15 | 01/22 10:00 | 28 | Giovanni Fonio v Davide Galoppini | 6-1,6-2 | |
| ITF - Antalya M15 | 01/21 13:00 | 27 | Paul Woerner v Giovanni Fonio | 1-6,3-6 | |
| ITF - Antalya M15 | 01/20 15:00 | 26 | Calin Manda v Giovanni Fonio | 4-6,3-6 | |
| ITF - Antalya M15 | 01/19 12:40 | 25 | Aleksandar Tomas v Giovanni Fonio | 2-6,2-6 | |
| Challenger Antalya | 12/11 10:00 | 28 | [409] Oleg Prihodko v Giovanni Fonio [441] | 1-6,6-1,6-3 | |
| Challenger Antalya | 12/10 07:00 | 27 | [441] Giovanni Fonio v Nick Hardt [350] | 7-6,6-2 | |
| Challenger Antalya | 12/09 09:25 | 26 | [264] Ryan Peniston v Giovanni Fonio [441] | 6-1,4-6,4-6 | |
| Challenger Antalya | 12/08 12:30 | 25 | [466] Jakub Paul v Giovanni Fonio [441] | 1-6,0-6 | |
| Challenger Antalya | 11/29 07:30 | 14 | Marsel Ilhan v Giovanni Fonio | 6-4,3-6,6-4 | |
| Challenger Napoli | 10/11 08:00 | 14 | [303] Javier Barranco Cosano v Giovanni Fonio [437] | 7-5,6-3 | |
| ITF - Platja D'Aro M15 | 10/09 09:00 | 28 | [437] Giovanni Fonio v Jose Fco. Vidal Azorin [476] | 3-6,4-6 | |
| ITF - Platja D'Aro M15 | 10/08 10:00 | 27 | Giovanni Fonio v Maxime Chazal | 6-3,6-2 | |
| ITF - Platja D'Aro M15 | 10/07 13:35 | 26 | Giovanni Fonio v Manish Sureshkumar | 6-0,6-1 | |
| ITF - Platja D'Aro M15 | 10/06 10:15 | 25 | Giovanni Fonio v Vitali Shvets | 6-4,6-0 | |
| Challenger Lisbon | 09/26 14:00 | 14 | [458] Daniel Michalski v Giovanni Fonio [439] | 6-4,7-5 | |
| Challenger Bukareszt | 09/19 07:30 | 14 | [436] Giovanni Fonio v Oleksii Krutykh [380] | 3-6,1-6 | |
| Challenger Trieste | 07/26 12:35 | 19 | [328] Thiago A Tirante v Giovanni Fonio [442] | 6-3,6-3 | |
| Challenger Trieste | 07/25 11:35 | 14 | [438] Giovanni Fonio v Julian Ocleppo [360] | 3-6,6-4,7-5 | |
| ITF - Kottingbrunn M25 | 07/23 10:55 | 27 | Giovanni Fonio v Mate Valkusz | 4-6,0-6 | |
| ITF - Kottingbrunn M25 | 07/22 08:00 | 26 | Giovanni Fonio v Sandro Kopp | 6-1,7-5 | |
| ITF - Kottingbrunn M25 | 07/21 10:15 | 25 | Giovanni Fonio v Peter Makk | 6-3,7-6 | |
| Challenger Todi | 07/15 17:00 | 26 | [315] Alexander Ritschard v Giovanni Fonio [472] | 6-3,6-4 | |
| Challenger Todi | 07/13 11:00 | 25 | [472] Giovanni Fonio v Lorenzo Giustino [227] | 6-4,6-3 | |
| Challenger Todi | 07/12 13:00 | 19 | [472] Giovanni Fonio v Riccardo Balzerani [492] | 6-3,6-3 | |
| Challenger Todi | 07/11 08:00 | 14 | Giovanni Fonio v Alejandro Mendoza | 6-1,6-1 | |
| ITF - Casinalbo M25 | 07/07 08:35 | 26 | Gianmarco Ferrari v Giovanni Fonio | 6-4,7-6 |
Giovanni Fonio (born 7 May 1998) is an Italian tennis player. He took his first steps in tennis at the age of 5, at the Piazzano tennis club in Novara.
Fonio has a career high ATP singles ranking of 274 achieved on 4 Dicember 2023. He also has a career high doubles ranking of 406 achieved on 15 January 2024.
Fonio has won 2 ATP Challenger doubles title: at the 2023 Internazionali di Tennis del Friuli Venezia Giulia with Francesco Forti and at the 2021 Antalya Challenger III with Riccardo Bonadio.
The greatest victory achieved by Giovanni was certainly during the Yokkaichi Challenger in Japan, on 30 November 2023, when he beat the then top 100 player Yosuke Watanuki in 3 sets (3-6 / 6-2 / 7-5).
An important presence in high-level tournaments was certainly in May 2022 at the qualifiers at the Internazionali d’Italia, unfortunately he lost against Emil Ruusuvuori 2-1 (4-6 / 7-6 / 3-6).