| Challenger Vicenza | 05/29 10:50 | 19 | [250] Lorenzo Giustino v Nerman Fatic [278] | 2-6,2-6 | |
| Challenger Vicenza | 05/28 12:00 | 14 | [250] Lorenzo Giustino v Daniel Dutra Da Silva [327] | 6-4,4-6,6-1 | |
| French Open | 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 Barcelona | 04/18 09:00 | 24 | [223] Lorenzo Giustino v Alexander Shevchenko [98] | 2-6,2-6 | |
| ATP Barcelona | 04/16 10:15 | 19 | [224] Lorenzo Giustino v Geoffrey Blancaneaux [170] | 6-3,1-6,7-6 | |
| ATP Barcelona | 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 Girona | 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 | |
| Challenger Tenerife | 01/31 15:50 | 25 | [245] Lorenzo Giustino v Oleksii Krutykh [176] | 2-6,0-6 | |
| Challenger Tenerife | 01/30 10:00 | 19 | [245] Lorenzo Giustino v Gian Marco Moroni [347] | Retired | |
| Challenger Tenerife | 01/29 10:00 | 14 | [267] Lorenzo Giustino v Giovanni Fonio [366] | 6-3,6-4 | |
| Challenger Tenerife | 01/20 15:00 | 27 | [267] Lorenzo Giustino v Alexander Shevchenko [157] | 4-6,5-7 | |
| Challenger Tenerife | 01/19 15:00 | 26 | [220] Kimmer Coppejans v Lorenzo Giustino [267] | 3-6,3-6 | |
| Challenger Tenerife | 01/17 16:20 | 25 | [199] Stefan Kozlov v Lorenzo Giustino [267] | Retired |
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.