| Challenger Troyes | 07/06 11:00 | 26 | [331] Lucas Gerch v Lorenzo Giustino [258] | 3-6,6-3,3-6 | |
| Challenger Troyes | 07/05 10:05 | 25 | [295] Valentin Royer v Lorenzo Giustino [258] | 4-6,4-6 | |
| Challenger Modena | 06/26 17:40 | 25 | [256] Lorenzo Giustino v Nerman Fatic [251] | 6-7,2-6 | |
| Poznan, Poland | 06/20 08:30 | 25 | [117] Diaz Acosta, Facundo v Lorenzo Giustino [255] | 3-6,6-2,6-4 | |
| Challenger Perugia | 06/12 13:30 | 25 | [313] Pol M Tiffon v Lorenzo Giustino [250] | 6-3,6-3 | |
| Prostejov, Czech Republic | 06/04 11:25 | 14 | Lorenzo Giustino v Pedro Sakamoto | 6-4,6-7,6-7 | |
| Challenger - Vicence | 05/29 10:50 | 19 | [250] Lorenzo Giustino v Nerman Fatic [278] | 2-6,2-6 | |
| Challenger - Vicence | 05/28 12:00 | 14 | [250] Lorenzo Giustino v Daniel Dutra Da Silva [327] | 6-4,4-6,6-1 | |
| Open de France | 05/22 11:00 | 14 | [248] Lorenzo Giustino v Frederico Ferreira Silva [225] | 7-6,6-7,1-6 | |
| Challenger - Francavilla | 05/13 10:00 | 28 | [267] Lorenzo Giustino v Benoit Paire [160] | 3-6,2-6 | |
| Challenger - Francavilla | 05/12 11:55 | 27 | [217] Raphael Collignon v Lorenzo Giustino [267] | 6-7,2-6 | |
| Challenger - Francavilla | 05/10 09:30 | 26 | [267] Lorenzo Giustino v Dimitar Kuzmanov [211] | 1-6,7-6,6-2 | |
| Challenger - Francavilla | 05/08 14:00 | 25 | [267] Lorenzo Giustino v Mikhail Kukushkin [293] | 7-5,6-1 | |
| Challenger - Aix en Provence | 05/01 11:00 | 14 | [403] Benjamin Lock v Lorenzo Giustino [229] | 0-6,6-4,7-5 | |
| Challenger - Ostrava | 04/26 10:25 | 25 | [496] Jiri Vesely v Lorenzo Giustino [229] | 6-3,6-7,6-2 | |
| ATP - Barcelone | 04/18 09:00 | 24 | [223] Lorenzo Giustino v Alexander Shevchenko [98] | 2-6,2-6 | |
| ATP - Barcelone | 04/16 10:15 | 19 | [224] Lorenzo Giustino v Geoffrey Blancaneaux [170] | 6-3,1-6,7-6 | |
| ATP - Barcelone | 04/15 08:00 | 14 | [114] Otto Virtanen v Lorenzo Giustino [224] | 7-6,4-6,4-6 | |
| Challenger - Madrid | 04/12 12:25 | 26 | [194] Andrea Collarini v Lorenzo Giustino [224] | 6-2,3-6,6-2 | |
| Challenger - Madrid | 04/10 13:10 | 25 | [252] Omar Jasika v Lorenzo Giustino [221] | 4-6,6-4,2-6 | |
| Challenger Murcia | 04/04 09:00 | 25 | [274] Pablo Llamas Ruiz v Lorenzo Giustino [221] | 6-2,6-2 | |
| Challenger - Gérone | 03/27 13:30 | 25 | [323] Pablo Llamas Ruiz v Lorenzo Giustino [219] | 7-5,4-6,6-4 | |
| Challenger Las Franquesas del Valles | 03/23 11:05 | 26 | [219] Lorenzo Giustino v Ivan Gakhov [241] | 2-6,5-7 | |
| Challenger Las Franquesas del Valles | 03/21 15:00 | 25 | [219] Lorenzo Giustino v Rudolf Molleker [326] | 6-3,5-7,7-6 | |
| Challenger - Pune | 03/01 05:30 | 26 | [223] Lorenzo Giustino v Luca Nardi [151] | 7-6,0-6,4-6 | |
| Challenger - Pune | 02/28 05:00 | 25 | [245] Nam Hoang Ly v Lorenzo Giustino [223] | 1-6,1-6 | |
| Challenger - Bengaluru | 02/21 07:15 | 25 | [223] Lorenzo Giustino v James McCabe [346] | 2-6,6-7 | |
| Challenger Manama | 02/17 09:00 | 27 | [243] Lorenzo Giustino v Salvatore Caruso [380] | 5-7,2-6 | |
| Challenger Manama | 02/15 12:35 | 26 | [108] Francesco Passaro v Lorenzo Giustino [243] | 5-7,3-6 | |
| Challenger Manama | 02/14 08:00 | 25 | Lorenzo Giustino v Mohamed Safwat | 6-4,6-4 |
Lorenzo Giustino (Italian pronunciation: [loˈrɛntso dʒuˈstiːno]; born 10 September 1991, in Naples) is an Italian tennis player.
Giustino has a career-high ATP singles ranking of 127 achieved on 12 August 2019 and a career-high ATP doubles ranking of 311 achieved on 15 April 2019.
Giustino made his ATP main draw debut at the 2015 BRD Năstase Țiriac Trophy, where he qualified for the main draw.
Giustino made his Grand Slam debut at the 2020 Australian Open. He defeated Frenchman Corentin Moutet 0–6, 7–6 (7), 7–6 (3), 2–6, 18–16 in the first round of 2020 French Open as a first time main draw qualifier at this Major. The match was the second-longest in French Open history, lasting 6 hours, 5 minutes. It was his first ATP tour-level win.
He qualified for his first ATP 500 tournament at the 2021 Dubai Tennis Championships as a lucky loser receiving a bye into the second round after the withdrawal of tenth seed Borna Ćorić.
He qualified for his second ATP 500 at the 2023 Barcelona Open Banc Sabadell.