| Challenger - Francavilla | 04/28 14:55 | 27 | Ruben R. Hidalgo v Alessandro Giannessi | Retired | |
| Challenger - Francavilla | 04/28 14:45 | - | Ruben R Hidalgo v Alessandro Giannessi | 6-4,4-6,0-0 | |
| Challenger - Francavilla | 04/27 10:30 | 26 | [346] Lorenzo Sonego v Alessandro Giannessi [121] | 6-3,4-6,4-6 | |
| Challenger - Francavilla | 04/25 16:20 | 25 | [206] Stefanos Tsitsipas v Alessandro Giannessi [121] | 6-7,4-6 | |
| ATP Monte Carlo Qual | 04/15 14:00 | 45 | [70] Damir Dzumhur v Alessandro Giannessi [121] | 6-3,7-5 | |
| Challenger - Barletta | 04/14 12:25 | 27 | [161] Lukas Rosol v Alessandro Giannessi [121] | 2-6,6-3,6-3 | |
| Challenger - Barletta | 04/13 10:00 | 26 | [200] Nikola Milojevic v Alessandro Giannessi [121] | 1-6,3-6 | |
| Challenger - Barletta | 04/11 14:00 | 25 | [208] Riccardo Bellotti v Alessandro Giannessi [121] | 3-6,3-6 | |
| Davis Cup | 04/09 14:40 | 27 | [199] Joris De Loore v Alessandro Giannessi [122] | 4-6,6-7 | |
| Challenger - Santiago | 03/07 23:30 | 25 | [349] Simone Bolelli v Alessandro Giannessi [121] | Retired | |
| ATP Sao Paulo | 03/02 17:50 | 26 | Alessandro Giannessi v Fabio Fognini | 6-7,6-7 | |
| ATP Sao Paulo | 02/28 15:30 | 25 | Rogerio Dutra Silva v Alessandro Giannessi | 4-6,3-6 | |
| ATP Sao Paulo Qual | 02/26 14:00 | - | Alessandro Giannessi v Guido Andreozzi | Retired | |
| ATP Sao Paulo Qual | 02/25 15:30 | 26 | Alessandro Giannessi v Federico Coria | Retired | |
| ATP Rio De Janeiro Qual | 02/18 12:00 | 45 | Marco Cecchinato v Alessandro Giannessi | 7-6,6-7,6-2 | |
| ATP - Buenos Aires | 02/15 21:45 | 26 | Alessandro Giannessi v Pablo Carreno-Busta | 1-6,6-4,4-6 | |
| ATP - Buenos Aires | 02/14 22:50 | 25 | Rogerio Dutra Silva v Alessandro Giannessi | 7-5,6-7,4-6 | |
| ATP Buenos Aires Qual | 02/13 18:30 | 46 | Dusan Lajovic v Alessandro Giannessi | 3-6,6-3,1-6 | |
| ATP Buenos Aires Qual | 02/11 18:45 | 45 | Roberto Carballes Baena v Alessandro Giannessi | 4-6,4-6 | |
| ATP Quito | 02/07 21:55 | 25 | Alejandro Falla v Alessandro Giannessi | 6-4,6-3 | |
| Challenger - Koblenz | 01/19 10:00 | 26 | Nils Langer v Alessandro Giannessi | 6-2,6-0 | |
| Challenger - Koblenz | 01/17 11:15 | 25 | Franko Skugor v Alessandro Giannessi | 4-6,6-7 | |
| Australian Open 2017 Qual | 01/11 04:20 | 44 | Alessandro Giannessi v Jan Satral | 6-7,6-7 | |
| ATP - Doha | 01/03 17:30 | 25 | Tomas Berdych v Alessandro Giannessi | 7-6,6-2 | |
| ATP Doha Qual | 01/01 12:30 | 46 | Mirza Basic v Alessandro Giannessi | 4-6,2-6 | |
| ATP Doha Qual | 12/31 08:00 | 45 | Mousa Shanan Zayed v Alessandro Giannessi | 2-6,1-6 | |
| Challenger - Ortisei | 11/13 12:00 | 29 | Alessandro Giannessi v Stefano Napolitano | 4-6,1-6 | |
| Challenger - Ortisei | 11/12 14:35 | 28 | Lorenzo Sonego v Alessandro Giannessi | 6-3,5-7,4-6 | |
| Challenger - Ortisei | 11/11 16:00 | 27 | Alessandro Giannessi v Salvatore Caruso | 6-1,7-6 | |
| Challenger - Ortisei | 11/10 12:30 | 26 | Alessandro Giannessi v Adrian M-Maceiras | 7-6,6-7,6-1 |
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.