| Challenger Tigre | 01/10 16:30 | - | Juan Ignacio Londero v Alessandro Giannessi | View | |
| Challenger Tigre | 01/10 14:35 | 25 | [271] Juan Ignacio Londero v Alessandro Giannessi [247] | Retired | |
| Challenger Tigre | 01/07 14:00 | 28 | [151] Juan Manuel Cerundolo v Alessandro Giannessi [262] | 6-3,7-5 | |
| Challenger Tigre | 01/06 16:15 | 27 | Lautaro Midon v Alessandro Giannessi | 5-7,1-6 | |
| Challenger Tigre | 01/05 17:25 | 26 | [369] Andrey Chepelev v Alessandro Giannessi [262] | 4-6,4-6 | |
| Challenger Tigre | 01/04 13:00 | 25 | Luciano Emanuel Ambrogi v Alessandro Giannessi | 5-7,0-6 | |
| Challenger - Maia | 11/29 13:55 | 25 | [303] Alexandar Lazarov v Alessandro Giannessi [267] | 6-3,6-4 | |
| Challenger - Valencia | 11/22 09:00 | 25 | [268] Alessandro Giannessi v Nikolas S Izquierdo [263] | 2-6,4-6 | |
| Challenger - Valencia | 11/21 13:55 | 19 | [268] Alessandro Giannessi v Alvaro Lopez San Martin [401] | 4-6,0-6 | |
| Challenger - Valencia | 11/20 16:45 | 14 | [264] Alessandro Giannessi v Alberto Barroso Campos [395] | 7-5,6-1 | |
| Challenger - Coquimbo | 10/18 14:50 | 25 | [71] Federico Coria v Alessandro Giannessi [232] | 6-4,6-2 | |
| Challenger - Rio De Janeiro | 10/11 15:05 | 25 | [386] Remy Bertola v Alessandro Giannessi [232] | 6-3,6-7,6-4 | |
| Challenger - Campinas | 10/05 15:15 | 26 | [233] Alessandro Giannessi v Alexandre Muller [145] | 7-5,0-6,2-6 | |
| Challenger - Campinas | 10/04 16:20 | 25 | [163] Yannick Hanfmann v Alessandro Giannessi [233] | 6-4,6-7,6-7 | |
| Challenger - Genua | 09/20 13:30 | 25 | [217] Alessandro Giannessi v Pablo Andujar [117] | 4-6,6-4,2-6 | |
| Challenger - Como | 08/30 08:00 | 25 | [225] Alessandro Giannessi v Kenny de Schepper [359] | Retired | |
| Challenger - Como | 08/30 08:00 | 25 | Alessandro Giannessi v Mariano Navone | Cancelled | |
| Challenger - Santo Domingo | 08/18 18:00 | 26 | [235] Alessandro Giannessi v Pedro Cachin [88] | 1-6,2-6 | |
| Challenger - Santo Domingo | 08/17 02:20 | 25 | [235] Alessandro Giannessi v Roberto Quiroz [256] | Retired | |
| Challenger - San Benedetto | 07/26 19:55 | 25 | [231] Alessandro Giannessi v Giovanni Fonio [435] | 3-6,4-6 | |
| Challenger - Tampere | 07/19 14:30 | 25 | [188] Nicolas Kicker v Alessandro Giannessi [206] | 6-4,6-3 | |
| Challenger - Verona | 07/11 16:00 | 25 | [182] Alessandro Giannessi v Sebastian Ofner [230] | 3-6,3-6 | |
| Wimbledon | 06/20 13:40 | 14 | [190] Alessandro Giannessi v Hugo Grenier [136] | 1-6,1-6 | |
| Challenger - Parma | 06/15 15:05 | 26 | [221] Jozef Kovalik v Alessandro Giannessi [203] | 6-1,6-3 | |
| Challenger - Parma | 06/13 12:30 | 25 | [205] Salvatore Caruso v Alessandro Giannessi [203] | Retired | |
| Challenger - Perugia | 06/08 16:00 | 26 | [196] Alessandro Giannessi v Borna Coric [244] | 2-6,6-7 | |
| Challenger - Perugia | 06/07 08:30 | 25 | [276] Nerman Fatic v Alessandro Giannessi [196] | Retired | |
| Challenger - Forlì | 05/31 10:30 | 25 | [173] Alessandro Giannessi v Jaume Munar [87] | 2-6,2-6 | |
| French Open | 05/23 09:00 | 23 | [173] Alessandro Giannessi v Borna Gojo [223] | 4-6,7-6,7-6,6-7,4-6 | |
| French Open | 05/19 08:00 | 19 | [173] Alessandro Giannessi v Sebastian Ofner [218] | 4-6,6-1,2-6 |
Alessandro Giannessi (born 30 May 1990) is a professional Italian tennis player. On 24 July 2017 he reached his highest ATP singles ranking of world No. 84 while his best doubles ranking was No. 171 on 14 October 2013.
Giannessi made his Grand Slam debut at the 2016 US Open as a qualifier where he recorded his first Major win defeating Denis Kudla in five sets.
Giannessi was a singles semifinalist at the 2017 Croatia Open Umag.
At the 2021 French Open he made his debut at this Major after qualifying for the main draw with a win over Francisco Cerundolo.
At the 2022 French Open although he lost in the third round of qualifying to Sebastian Ofner he entered the main draw as a lucky loser.
He won his fourth Challenger title and first since 2019 at the 2023 Zadar Open this time with a win over Sebastian Ofner.