| Challenger - Poznań | 06/07 09:30 | 27 | [395] Andrea Vavassori v Alessandro Giannessi [164] | 7-6,6-1 | |
| Challenger - Poznań | 06/06 11:10 | 26 | [164] Alessandro Giannessi v Daniel Masur [251] | 7-6,4-6,6-3 | |
| Challenger - Poznań | 06/05 12:20 | 25 | [164] Alessandro Giannessi v Sumit Nagal [280] | 7-5,3-6,6-3 | |
| Challenger - Vicenza | 06/02 13:00 | 29 | [164] Alessandro Giannessi v Filippo Baldi [163] | 7-5,6-2 | |
| Challenger - Vicenza | 06/01 14:00 | 28 | [142] Gianluca Mager v Alessandro Giannessi [164] | 3-6,3-6 | |
| Challenger - Vicenza | 05/31 11:25 | 27 | [185] Marc Polmans v Alessandro Giannessi [164] | 4-6,5-7 | |
| Challenger - Vicenza | 05/31 07:30 | 26 | [164] Alessandro Giannessi v Adrian Menendez-Maceiras [150] | 6-2,6-0 | |
| Challenger - Vicenza | 05/30 10:55 | 25 | [164] Alessandro Giannessi v Federico Gaio [202] | 6-3,6-2 | |
| French Open | 05/20 08:00 | 44 | [303] Alexandre Muller v Alessandro Giannessi [165] | 5-7,7-6,6-1 | |
| Challenger - Lissabon | 05/15 14:00 | 25 | [204] Andrea Arnaboldi v Alessandro Giannessi [168] | Retired | |
| ATP Budapest | 04/20 08:30 | 64 | [91] Miomir Kecmanovic v Alessandro Giannessi [162] | 6-3,6-4 | |
| Challenger Sophia Antipolis | 04/04 14:30 | 26 | [207] Roberto Marcora v Alessandro Giannessi [157] | 6-2,6-3 | |
| Challenger Sophia Antipolis | 04/03 14:15 | 25 | [363] Oriol R.-Batalla v Alessandro Giannessi [157] | 5-7,2-6 | |
| Challenger - Marbella | 03/29 11:50 | 27 | [67] Benoit Paire v Alessandro Giannessi [166] | 5-7,6-4,7-6 | |
| Challenger - Marbella | 03/28 10:00 | 26 | [166] Alessandro Giannessi v Raul Brancaccio [390] | 4-6,7-6,6-3 | |
| Challenger - Marbella | 03/26 15:35 | 25 | [166] Alessandro Giannessi v Enzo Couacaud [245] | 6-2,5-7,7-6 | |
| Challenger - Santiago | 03/08 19:35 | 27 | [169] Alessandro Giannessi v Thomaz Bellucci [232] | 6-3,4-6,4-6 | |
| Challenger - Santiago | 03/07 14:00 | 26 | [169] Alessandro Giannessi v Facundo Arguello [195] | 4-6,6-4,6-1 | |
| Challenger - Santiago | 03/05 19:00 | 25 | [169] Alessandro Giannessi v Andrea Collarini [318] | 7-6,5-7,6-4 | |
| ATP Sao Paulo | 02/27 15:30 | 25 | [168] Alessandro Giannessi v Laslo Djere [37] | 6-7,6-4,4-6 | |
| ATP Sao Paulo | 02/24 15:00 | 164 | [164] Alessandro Giannessi v Kimmer Coppejans [193] | 6-4,6-2 | |
| ATP Sao Paulo | 02/23 17:05 | 64 | [164] Alessandro Giannessi v Joao Souza [416] | 7-6,6-3 | |
| ATP - Rio de Janeiro | 02/16 18:00 | 64 | [69] Juan Ignacio Londero v Alessandro Giannessi [170] | 7-6,6-1 | |
| ATP - Buenos Aires | 02/10 16:55 | 164 | [113] Lorenzo Sonego v Alessandro Giannessi [168] | Retired | |
| ATP - Buenos Aires | 02/09 19:00 | 64 | [168] Alessandro Giannessi v Marco Trungelliti [117] | 6-4,6-1 | |
| ATP - Córdoba | 02/07 23:10 | 26 | [20] Diego Schwartzman v Alessandro Giannessi [168] | 6-7,6-3,6-0 | |
| ATP - Córdoba | 02/05 18:30 | 25 | [168] Alessandro Giannessi v Thiago Seyboth Wild [451] | 6-7,7-5,7-6 | |
| ATP - Córdoba | 02/03 20:25 | 164 | [114] Paolo Lorenzi v Alessandro Giannessi [167] | 7-6,4-6,6-7 | |
| ATP - Córdoba | 02/02 21:25 | 64 | Facundo D Acosta v Alessandro Giannessi | Retired | |
| Challenger - Punta del Este | 01/23 15:40 | 25 | [331] Marcelo T B Vera v Alessandro Giannessi [161] | 6-4,6-4 |
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.