| Poznan, Poland | 06/07 09:00 | 26 | Estrella Burgos, Victor v Alessandro Giannessi | 6-4,3-6,3-6 | |
| Poznan, Poland | 06/05 10:40 | 25 | [199] Alessandro Giannessi v Sousa, Pedro [120] | 6-2,6-3 | |
| French Open Qual | 05/25 11:35 | 46 | [198] Alessandro Giannessi v Gulbis, Ernests [162] | 6-4,4-6,2-6 | |
| French Open Qual | 05/24 11:10 | 45 | [198] Alessandro Giannessi v Kamke, Tobias [224] | 7-6,6-2 | |
| French Open Qual | 05/21 15:20 | 44 | [112] Gerald Melzer v Alessandro Giannessi [198] | 6-7,2-6 | |
| Challenger - Heilbronn | 05/15 11:35 | 25 | [142] Henri Laaksonen v Alessandro Giannessi [192] | 4-6,6-4,6-4 | |
| Challenger - Rome | 05/09 08:45 | 26 | [197] Alessandro Giannessi v Pavlasek, Adam [245] | 4-6,1-6 | |
| Challenger - Rome | 05/08 08:30 | 25 | [262] Viola, Matteo v Alessandro Giannessi [197] | 2-6,4-6 | |
| ATP Estoril Qual | 04/28 11:00 | 44 | [190] Joao Domingues v Alessandro Giannessi [162] | 7-5,6-1 | |
| ATP Barcelona Qual | 04/21 08:00 | 45 | [107] Fratangelo, Bjorn v Alessandro Giannessi [164] | 7-5,6-4 | |
| Challenger - Barletta | 04/11 13:00 | 26 | [237] Marco Trungelliti v Alessandro Giannessi [158] | Retired | |
| Challenger - Barletta | 04/10 09:40 | 25 | [483] Zsombor Piros v Alessandro Giannessi [158] | 2-6,1-6 | |
| Challenger - Barletta | 04/10 08:00 | - | Lorenzo Sonego v Alessandro Giannessi | Cancelled | |
| Alicante, Spain | 04/04 11:30 | 26 | Vilella Martinez, Mario v Alessandro Giannessi | Retired | |
| Alicante, Spain | 04/03 08:00 | 25 | [302] Ivan Gakhov v Alessandro Giannessi [161] | 1-6,6-7 | |
| Marbella, Spain | 03/27 12:25 | 25 | [136] Ramkumar Ramanathan v Alessandro Giannessi [161] | 6-4,3-6,6-3 | |
| Challenger - Santiago | 03/06 14:00 | 25 | Jozef Kovalik v Alessandro Giannessi | 6-3,2-6,6-2 | |
| Challenger - Punta del Este | 03/02 21:00 | 28 | Bolelli, Simone v Alessandro Giannessi | 6-2,7-5 | |
| Challenger - Punta del Este | 03/01 18:30 | 27 | Jozef Kovalik v Alessandro Giannessi | 6-7,6-2,6-7 | |
| Challenger - Punta del Este | 02/28 18:30 | 26 | Galarza, Juan Ignacio v Alessandro Giannessi | 0-6,4-6 | |
| Challenger - Punta del Este | 02/26 17:00 | 25 | Hugo Dellien v Alessandro Giannessi | 6-7,6-4,4-6 | |
| ATP Rio De Janeiro Qual | 02/18 19:00 | - | Roberto Carballes Baena v Alessandro Giannessi | 6-3,6-2 | |
| ATP Rio De Janeiro Qual | 02/17 18:00 | 26 | Clezar, Guilherme v Alessandro Giannessi | 7-6,4-6,3-6 | |
| ATP Buenos Aires Qual | 02/10 19:40 | 26 | Hernan Casanova v Alessandro Giannessi | 7-6,6-4 | |
| Quito, Ecuador | 02/08 19:30 | 26 | Thiago Monteiro v Alessandro Giannessi | 7-6,4-6,7-5 | |
| Quito, Ecuador | 02/07 17:00 | 25 | Alessandro Giannessi v Polansky, Peter | 6-3,6-4 | |
| ATP Quito Qual | 02/04 18:35 | - | Alessandro Giannessi v Federico Gaio | 6-3,6-7,6-7 | |
| ATP Quito Qual | 02/03 18:10 | 26 | Alessandro Giannessi v Londero, Juan Ignacio | 6-4,6-4 | |
| Australian Open Qual | 01/12 04:35 | 45 | Ernesto Escobedo v Alessandro Giannessi | 6-3,6-2 | |
| Australian Open Qual | 01/10 08:20 | 44 | Alessandro Giannessi v Sumit Nagal | 7-6,3-6,6-3 |
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.