| 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 | |
| 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 |
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.