| Challenger - Cagliari | 05/02 08:30 | 19 | [246] Alessandro Giannessi v Alexander Erler [36] | 7-5,6-1 | |
| Challenger - Florianopolis | 04/21 16:15 | 27 | [253] Alessandro Giannessi v Benjamin Hassan [295] | 6-3,4-6,6-7 | |
| Challenger - Florianopolis | 04/20 13:00 | 26 | [253] Alessandro Giannessi v Pedro B Dias [352] | 6-4,6-4 | |
| Challenger - Florianopolis | 04/19 13:00 | 25 | [253] Alessandro Giannessi v Juan Bautista Otegui [402] | 6-2,6-3 | |
| Challenger - Madrid | 04/09 12:30 | 14 | Alessandro Giannessi v David Jorda Sanchis | 6-3,6-7,3-6 | |
| ATP - Estoril | 04/03 17:50 | 25 | [224] Alessandro Giannessi v Fabio Fognini [97] | 2-6,1-6 | |
| ATP - Estoril | 04/02 11:00 | 19 | [128] Fabian Marozsan v Alessandro Giannessi [261] | 6-4,6-7,4-6 | |
| ATP - Estoril | 04/01 12:15 | 14 | [261] Alessandro Giannessi v Oleksii Krutykh [167] | 1-6,7-5,6-1 | |
| Challenger - Sanremo | 03/28 10:20 | 25 | [124] Giulio Zeppieri v Alessandro Giannessi [261] | 6-1,6-1 | |
| Challenger - Zadar | 03/26 10:00 | 29 | [137] Sebastian Ofner v Alessandro Giannessi [261] | 4-6,7-5,6-7 | |
| Challenger - Zadar | 03/25 12:00 | 28 | [261] Alessandro Giannessi v Arthur Cazaux [218] | 6-3,6-4 | |
| Challenger - Zadar | 03/24 11:20 | 27 | [261] Alessandro Giannessi v Zsombor Piros [185] | 7-6,6-2 | |
| Challenger - Zadar | 03/23 10:00 | 26 | [261] Alessandro Giannessi v Nino Serdarusic [249] | 7-6,6-3 | |
| Challenger - Zadar | 03/21 14:10 | 25 | [221] Manuel Guinard v Alessandro Giannessi [261] | 4-6,2-6 | |
| Challenger - Szekesfehervar | 03/16 09:00 | 26 | [235] Alessandro Giannessi v Flavio Cobolli [165] | 4-6,0-6 | |
| Challenger - Szekesfehervar | 03/14 14:10 | 25 | [295] Nikolas S Izquierdo v Alessandro Giannessi [235] | 4-6,7-6,4-6 | |
| Challenger - Antalya | 03/09 08:00 | 26 | [235] Alessandro Giannessi v Fabian Marozsan [163] | 6-7,2-6 | |
| Challenger - Antalya | 03/07 07:00 | 25 | [235] Alessandro Giannessi v Lucas Gerch [316] | 7-6,6-1 | |
| Challenger - Manama | 02/14 09:30 | 25 | [115] Tomas Machac v Alessandro Giannessi [233] | 6-2,2-6,6-2 | |
| Challenger - Tenerife | 02/10 14:10 | 27 | [409] Stefano Travaglia v Alessandro Giannessi [255] | 6-3,6-4 | |
| Challenger - Tenerife | 02/09 15:00 | 26 | [255] Alessandro Giannessi v Raul Brancaccio [124] | 6-3,6-2 | |
| Challenger - Tenerife | 02/08 11:00 | 25 | [255] Alessandro Giannessi v Mikhail Kukushkin [217] | 6-4,0-6,6-3 | |
| Challenger - Tenerife | 01/31 18:15 | 25 | [252] Alessandro Giannessi v Matteo Arnaldi [130] | 3-6,7-6,3-6 | |
| Challenger - Piracicaba | 01/17 18:20 | 25 | [233] Alessandro Giannessi v Camilo Ugo Carabelli [127] | 4-6,6-3,1-6 | |
| Challenger - Tigre | 01/14 16:00 | 28 | [325] Jesper De Jong v Alessandro Giannessi [247] | 6-4,5-7,6-1 | |
| Challenger - Tigre | 01/13 14:30 | 27 | [248] Mariano Navone v Alessandro Giannessi [247] | 7-6,5-7,1-6 | |
| Challenger - Tigre | 01/11 19:05 | 26 | [348] Pedro B Dias v Alessandro Giannessi [247] | 2-6,2-6 | |
| 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 |
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.