| Challenger - San Benedetto | 07/20 17:00 | 27 | [210] Andrea Arnaboldi v Lorenzo Giustino [247] | 3-6,4-6 | |
| Challenger - San Benedetto | 07/18 15:20 | 26 | [251] Tomislav Brkic v Lorenzo Giustino [247] | 1-6,6-7 | |
| Challenger - San Benedetto | 07/16 17:20 | 25 | [247] Lorenzo Giustino v Ricardo Ojeda Lara [195] | 6-3,6-0 | |
| Challenger Recanati | 07/06 17:45 | 27 | [146] Adrian Menendez-Maceiras v Lorenzo Giustino [258] | 6-4,6-2 | |
| Challenger Recanati | 07/05 19:00 | 26 | [258] Lorenzo Giustino v Antoine Hoang [231] | 6-3,6-7,6-0 | |
| Challenger Recanati | 07/03 17:50 | 25 | [258] Lorenzo Giustino v Andrea Basso [317] | 4-6,6-4,6-4 | |
| Challenger - Milan | 06/27 13:00 | 26 | [266] Lorenzo Giustino v Joao Domingues [258] | 6-7,2-6 | |
| Challenger - Milan | 06/25 12:30 | 25 | [266] Lorenzo Giustino v Maximilian Neuchrist [273] | 6-3,6-2 | |
| Challenger - Blois | 06/19 08:30 | 25 | [282] Scott Griekspoor v Lorenzo Giustino [266] | 6-4,6-1 | |
| Challenger - Shymkent | 06/08 08:00 | 28 | [138] Yannick Hanfmann v Lorenzo Giustino [264] | 6-1,6-0 | |
| Challenger - Shymkent | 06/07 07:30 | 27 | [264] Lorenzo Giustino v Kevin Krawietz [358] | 7-5,4-6,6-3 | |
| Challenger - Shymkent | 06/06 08:10 | 26 | [182] Mohamed Safwat v Lorenzo Giustino [264] | 4-6,7-6,4-6 | |
| Challenger - Shymkent | 06/05 08:20 | 25 | [225] Danilo Petrovic v Lorenzo Giustino [264] | Retired | |
| Challenger Mestre | 05/25 13:50 | 27 | [276] Lorenzo Giustino v Gianluigi Quinzi [243] | 6-2,6-7,3-6 | |
| Challenger Mestre | 05/24 09:00 | 26 | [276] Lorenzo Giustino v Liam Caruana [418] | 6-1,6-1 | |
| Challenger Mestre | 05/21 13:25 | 25 | [276] Lorenzo Giustino v Carlos Gomez-Herrera [271] | 7-5,6-4 | |
| Challenger - Lissabon | 05/17 16:50 | 26 | [129] Pedro Sousa v Lorenzo Giustino [255] | 6-2,6-0 | |
| Challenger - Lissabon | 05/15 17:05 | 25 | [255] Lorenzo Giustino v Joris De Loore [343] | 7-5,1-6,7-6 | |
| Challenger Braga | 05/09 10:00 | 26 | [253] Lorenzo Giustino v Alex De Minaur [109] | 5-7,7-5,2-6 | |
| Challenger Braga | 05/07 13:30 | 25 | [253] Lorenzo Giustino v Scott Griekspoor [278] | 4-6,6-3,6-3 | |
| Challenger - Ostrava | 05/02 10:30 | 26 | [265] Gianluigi Quinzi v Lorenzo Giustino [250] | 6-3,6-2 | |
| Challenger - Ostrava | 04/30 15:15 | 25 | Lorenzo Giustino v Patrik Rikl | 6-3,7-6 | |
| ATP Barcelona Qual | 04/21 11:10 | 45 | [267] Lorenzo Giustino v Jozef Kovalik [152] | 7-6,2-6,5-7 | |
| ITF Spain F9 | 04/19 13:40 | 26 | [267] Lorenzo Giustino v Javier Barranco Cosano [457] | 4-6,6-7 | |
| ITF Spain F9 | 04/17 10:25 | 25 | Lorenzo Giustino v Omar Salman | 6-1,6-1 | |
| ITF Italy F7 | 04/14 12:00 | 29 | [408] Gianluca Mager v Lorenzo Giustino [234] | 4-6,1-6 | |
| ITF Italy F7 | 04/13 13:30 | 28 | [234] Lorenzo Giustino v Andrea Collarini [224] | 2-6,6-4,7-5 | |
| ITF Italy F7 | 04/12 14:50 | 27 | [454] Bruno Sant'anna v Lorenzo Giustino [234] | 3-6,5-7 | |
| ITF Italy F7 | 04/11 14:00 | 26 | [393] Lenny Hampel v Lorenzo Giustino [234] | 1-6,4-6 | |
| ITF Italy F7 | 04/10 14:45 | 25 | Billy Harris v Lorenzo Giustino | 1-6,0-6 |
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.