| 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 | |
| Challenger Tigre | 01/04 13:00 | 25 | Luciano Emanuel Ambrogi v Alessandro Giannessi | 5-7,0-6 | |
| Challenger Maia | 11/29 13:55 | 25 | [303] Alexandar Lazarov v Alessandro Giannessi [267] | 6-3,6-4 | |
| Challenger Valencia | 11/22 09:00 | 25 | [268] Alessandro Giannessi v Nikolas S Izquierdo [263] | 2-6,4-6 | |
| Challenger Valencia | 11/21 13:55 | 19 | [268] Alessandro Giannessi v Alvaro Lopez San Martin [401] | 4-6,0-6 | |
| Challenger Valencia | 11/20 16:45 | 14 | [264] Alessandro Giannessi v Alberto Barroso Campos [395] | 7-5,6-1 | |
| Challenger Coquimbo | 10/18 14:50 | 25 | [71] Federico Coria v Alessandro Giannessi [232] | 6-4,6-2 | |
| Challenger Rio de Janeiro | 10/11 15:05 | 25 | [386] Remy Bertola v Alessandro Giannessi [232] | 6-3,6-7,6-4 | |
| Challenger Campinas | 10/05 15:15 | 26 | [233] Alessandro Giannessi v Alexandre Muller [145] | 7-5,0-6,2-6 | |
| Challenger Campinas | 10/04 16:20 | 25 | [163] Yannick Hanfmann v Alessandro Giannessi [233] | 6-4,6-7,6-7 | |
| Challenger Janov | 09/20 13:30 | 25 | [217] Alessandro Giannessi v Pablo Andujar [117] | 4-6,6-4,2-6 | |
| Challenger Como | 08/30 08:00 | 25 | [225] Alessandro Giannessi v Kenny de Schepper [359] | Retired | |
| Challenger Como | 08/30 08:00 | 25 | Alessandro Giannessi v Mariano Navone | Cancelled | |
| Challenger Santo Domingo | 08/18 18:00 | 26 | [235] Alessandro Giannessi v Pedro Cachin [88] | 1-6,2-6 | |
| Challenger Santo Domingo | 08/17 02:20 | 25 | [235] Alessandro Giannessi v Roberto Quiroz [256] | Retired | |
| Challenger San Benedetto | 07/26 19:55 | 25 | [231] Alessandro Giannessi v Giovanni Fonio [435] | 3-6,4-6 | |
| Challenger Tampere | 07/19 14:30 | 25 | [188] Nicolas Kicker v Alessandro Giannessi [206] | 6-4,6-3 | |
| Challenger Verona | 07/11 16:00 | 25 | [182] Alessandro Giannessi v Sebastian Ofner [230] | 3-6,3-6 | |
| Wimbledon | 06/20 13:40 | 14 | [190] Alessandro Giannessi v Hugo Grenier [136] | 1-6,1-6 | |
| Challenger Parma | 06/15 15:05 | 26 | [221] Jozef Kovalík v Alessandro Giannessi [203] | 6-1,6-3 | |
| Challenger Parma | 06/13 12:30 | 25 | [205] Salvatore Caruso v Alessandro Giannessi [203] | Retired | |
| Challenger Perugia | 06/08 16:00 | 26 | [196] Alessandro Giannessi v Borna Coric [244] | 2-6,6-7 | |
| Challenger Perugia | 06/07 08:30 | 25 | [276] Nerman Fatic v Alessandro Giannessi [196] | Retired |
Alessandro Giannessi (* 30. května 1990 La Spezia) je italský profesionální tenista hrající levou rukou. Ve své dosavadní kariéře na okruhu ATP World Tour nevyhrál žádný turnaj. Na challengerech ATP a okruhu ITF získal do září 2016 šest titulů ve dvouhře a sedm ve čtyřhře.
Na žebříčku ATP byl ve dvouhře nejvýše klasifikován v dubnu 2012 na 126. místě a ve čtyřhře pak v říjnu 2013 na 171. místě. Trénují ho Gabrio Castrichella a Eduardo Infantino.
V italském daviscupovém týmu neodehrál žádné utkání.