| ITF Italy F17 | 07/08 13:30 | - | Della Tommasina, Davide v Alessandro Giannessi | 3-6,4-6 | |
| ITF Italy F17 | 07/07 15:10 | - | Andres Gabriel Ciurletti v Alessandro Giannessi | 1-6,2-6 | |
| Challenger Padova | 07/03 12:00 | 27 | Martin, Andrej v Alessandro Giannessi | 6-2,7-6 | |
| Challenger Padova | 07/01 12:45 | 26 | Alessandro Giannessi v Bellotti, Riccardo | 3-6,6-1,6-4 | |
| Challenger Padova | 06/30 09:30 | 25 | Alessandro Giannessi v Andrey Rublev | 3-6,6-2,6-4 | |
| Challenger Padova Qual | 06/29 10:00 | 44 | Barrientos, Nicolas v Alessandro Giannessi | 2-6,2-6 | |
| Milan, Italy | 06/21 09:00 | 44 | Benoit Paire v Alessandro Giannessi | 6-3,6-3 | |
| ITF Italy F13 | 06/12 15:30 | - | Alessandro Giannessi v Trubrig, Christian | 6-4,3-6,7-6 | |
| ITF Italy F13 | 06/11 13:30 | - | Alessandro Giannessi v Fortuna, Claudio | 6-2,6-3 | |
| ITF Italy F13 | 06/10 12:30 | - | Alessandro Giannessi v Riccardo Bonadio | 6-3,6-0 | |
| ITF Italy F13 | 06/09 17:00 | - | Mina, Gianni v Alessandro Giannessi | 6-7,3-6 | |
| ITF Italy F12 | 06/06 13:00 | - | Alessandro Giannessi v Yann Marti | 6-7,7-5,6-4 | |
| ITF Italy F12 | 06/05 14:30 | - | Tatlot, Johan Sebastien v Alessandro Giannessi | 3-6,5-7 | |
| ITF Italy F12 | 06/04 11:00 | - | Ghedin, Riccardo v Alessandro Giannessi | 2-6,1-6 | |
| ITF Italy F12 | 06/03 11:40 | - | Alessandro Giannessi v Martniez, Mateo Nicolas | 6-4,6-3 | |
| ITF Italy F11 | 05/26 14:50 | - | Alessandro Giannessi v Tabatruong, Maxime | 7-5,4-6,5-7 | |
| Challenger Biella | 09/09 11:25 | 25 | Alessandro Giannessi v Henri Laaksonen | 6-7,6-4,2-6 | |
| Genoa, Italy | 09/02 09:30 | 25 | Alessandro Giannessi v Guido Andreozzi | 5-7,2-6 | |
| Challenger Cortina | 07/30 15:20 | 25 | Alessandro Giannessi v Trusendi, Walter | 3-6,6-3,3-6 | |
| ITF Italy F23 | 07/18 14:25 | - | Federico Gaio v Alessandro Giannessi | Retired | |
| ITF Italy F23 | 07/17 13:00 | - | Estevez Maximiliano v Alessandro Giannessi | 6-7,4-6 | |
| ITF Italy F23 | 07/15 14:05 | - | Zmak, Deni v Alessandro Giannessi | 6-7,3-6 | |
| Challenger San Benedetto | 07/10 19:50 | 26 | Haider-Maurer, Andreas v Alessandro Giannessi | 6-1,6-3 | |
| Challenger San Benedetto | 07/08 14:40 | 25 | Alessandro Giannessi v Granollers, Gerard | 6-1,6-1 | |
| Challenger Todi | 07/02 08:00 | 25 | Alessandro Giannessi v Gonzalez, Maximo | 6-7,2-6 | |
| Challenger Padova | 06/27 11:00 | 27 | Alessandro Giannessi v Samper-Montana, Jordi | 4-6,5-7 | |
| Challenger Padova | 06/26 09:30 | 26 | Ungur, Adrian v Alessandro Giannessi | 5-7,0-6 | |
| Challenger Milan Qual | 06/16 09:20 | 44 | Alessandro Giannessi v Lizariturry, Juan | 4-6,4-6 | |
| Challenger Mestre | 06/05 09:30 | 26 | Alessandro Giannessi v Cuevas, Pablo | 0-6,4-6 | |
| Challenger Mestre | 06/04 11:15 | 25 | Salvatore Caruso v Alessandro Giannessi | 6-7,3-6 |
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.