| Wimbledon | 06/24 14:15 | 44 | [213] Yannick Hanfmann v Alessandro Giannessi [163] | 7-5,7-5 | |
| Challenger Parma | 06/19 10:05 | 25 | [370] Julian Lenz v Alessandro Giannessi [162] | 6-1,6-4 | |
| Challenger Poznan | 06/07 09:30 | 27 | [395] Andrea Vavassori v Alessandro Giannessi [164] | 7-6,6-1 | |
| Challenger Poznan | 06/06 11:10 | 26 | [164] Alessandro Giannessi v Daniel Masur [251] | 7-6,4-6,6-3 | |
| Challenger Poznan | 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 Lisabon | 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 |
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.