| ITF - M25 Santa Margherita | 04/19 14:10 | 25 | Giovanni Fonio v Toby Martin | 6-0,6-2 | |
| ITF - M25 Santa Margherita | 04/12 16:15 | 25 | [489] Matteo Gigante v Giovanni Fonio [454] | 4-6,7-5,7-6 | |
| Challenger Sanremo | 04/04 08:00 | 19 | [455] Giovanni Fonio v Mate Valkusz [402] | 7-5,4-6,4-6 | |
| Challenger Sanremo | 04/03 09:30 | 14 | [416] Giovanni Fonio v Alexander Weis [468] | 6-4,6-4 | |
| Challenger - Lugano | 03/27 12:35 | 14 | [299] Bemelmans, Ruben v Giovanni Fonio [416] | 7-5,6-4 | |
| ITF M25 Opatija | 03/22 10:45 | 25 | [489] Francesco Passaro v Giovanni Fonio [414] | 6-0,4-6,6-2 | |
| ITF M25 Rovinj | 03/15 12:35 | 25 | [362] Ergi Kirkin v Giovanni Fonio [414] | 6-4,7-6 | |
| ITF M25 Porec | 03/09 10:45 | 25 | [335] Filip Misolic v Giovanni Fonio [414] | 7-6,6-4 | |
| ITF - M25 Antalya | 02/26 09:15 | 27 | [367] Daniel Michalski v Giovanni Fonio [408] | 6-3,4-6,7-5 | |
| ITF - M25 Antalya | 02/25 12:30 | 26 | Giovanni Fonio v Andrea Picchione | Retired | |
| ITF - M25 Antalya | 02/22 11:00 | 25 | Togan Tokac v Giovanni Fonio | 1-6,1-6 | |
| ITF - M25 Antalya | 02/15 11:25 | 25 | [330] Miljan Zekic v Giovanni Fonio [412] | 6-2,6-4 | |
| ITF - M15 Antalya | 01/29 15:15 | 27 | [411] Giovanni Fonio v Corentin Denolly [450] | 6-7,2-6 | |
| ITF - M15 Antalya | 01/29 11:30 | 26 | Giovanni Fonio v S Mert Ozdemir | 6-2,6-2 | |
| ITF - M15 Antalya | 01/28 09:00 | 25 | Giovanni Fonio v Canas Garcia, Juan Pablo | 7-5,6-2 | |
| ITF - M15 Antalya | 01/23 08:50 | 29 | [479] Cezar Cretu v Giovanni Fonio [411] | 1-6,4-6 | |
| ITF - M15 Antalya | 01/22 10:00 | 28 | Giovanni Fonio v Galoppini, Davide | 6-1,6-2 | |
| ITF - M15 Antalya | 01/21 13:00 | 27 | Paul Woerner v Giovanni Fonio | 1-6,3-6 | |
| ITF - M15 Antalya | 01/20 15:00 | 26 | Manda, Calin v Giovanni Fonio | 4-6,3-6 | |
| ITF - M15 Antalya | 01/19 12:40 | 25 | Tomas, Aleksandar 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 M15 Platja D'Aro | 10/09 09:00 | 28 | [437] Giovanni Fonio v Vidal Azorin, Jose Fco [476] | 3-6,4-6 | |
| ITF M15 Platja D'Aro | 10/08 10:00 | 27 | Giovanni Fonio v Maxime Chazal | 6-3,6-2 | |
| ITF M15 Platja D'Aro | 10/07 13:35 | 26 | Giovanni Fonio v Manish Sureshkumar | 6-0,6-1 | |
| ITF M15 Platja D'Aro | 10/06 10:15 | 25 | Giovanni Fonio v Vitali Shvets | 6-4,6-0 |
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).