| ITF Italy F35 | 10/25 17:25 | 26 | Trusendi, Walter v Lorenzo Giustino | 7-6,0-6,6-7 | |
| ITF Italy F35 | 10/23 18:25 | 25 | Raul Brancaccio v Lorenzo Giustino | 6-7,2-6 | |
| ITF Italy F34 | 10/20 13:00 | 28 | [261] Lorenzo Giustino v Gimeno-Traver, Daniel [497] | 3-6,6-3,3-6 | |
| ITF Italy F34 | 10/19 14:55 | 27 | [261] Lorenzo Giustino v Giacalone, Omar [404] | 6-0,7-5 | |
| ITF Italy F34 | 10/18 13:00 | 26 | Lorenzo Giustino v Madaras, Dragos Nicolae | 6-3,6-3 | |
| ITF Italy F34 | 10/17 13:00 | 25 | Lorenzo Giustino v Lebedyn, Alexander | 6-3,6-1 | |
| ITF Italy F33 | 10/11 15:20 | 26 | [230] Andrea Vavassori v Lorenzo Giustino [261] | 6-1,6-2 | |
| ITF Italy F33 | 10/10 12:55 | 25 | [295] Trusendi, Walter v Lorenzo Giustino [261] | 3-6,6-7 | |
| Rome II, Italy | 09/26 09:00 | 25 | Lorenzo Giustino v Heras, Patricio | 1-6,3-6 | |
| Challenger Sibiu | 09/18 09:00 | 25 | [129] Stefano Travaglia v Lorenzo Giustino [198] | 6-2,6-0 | |
| Challenger Banja Luka | 09/13 08:00 | 25 | [313] Brkic, Tomislav v Lorenzo Giustino [198] | 6-4,6-4 | |
| ITF Italy F28 | 09/05 14:30 | 25 | Lorenzo Giustino v Marcora, Roberto | 3-6,4-6 | |
| US Open, New York, USA, Qualifying | 08/23 20:35 | 44 | [254] Robert, Stephane v Lorenzo Giustino [189] | 6-4,6-2 | |
| Cordenons, Italy | 08/19 17:00 | 28 | [279] Elias Ymer v Lorenzo Giustino [197] | 6-2,6-1 | |
| Cordenons, Italy | 08/18 18:15 | 27 | Lorenzo Giustino v Andrea Pellegrino | 6-3,6-3 | |
| Cordenons, Italy | 08/17 12:00 | 26 | [197] Lorenzo Giustino v Munoz-De la Nava, Daniel [418] | 3-6,6-2,6-3 | |
| Cordenons, Italy | 08/15 14:35 | 25 | [197] Lorenzo Giustino v Quinzi, Gianluigi [260] | 4-6,6-2,6-1 | |
| Portoroz, Slovénie | 08/08 08:00 | 25 | [199] Lorenzo Giustino v Matteo Berrettini [162] | 6-3,3-6,4-6 | |
| Challenger Biella | 08/01 08:00 | 25 | Constant Lestienne v Lorenzo Giustino | 7-5,4-6,6-4 | |
| Gstaad, Switzerland | 07/24 14:30 | 25 | [192] Lorenzo Giustino v Istomin, Denis [82] | 3-6,2-6 | |
| ATP Gstaad Qual | 07/23 11:15 | 46 | [137] Souza, Joao Olavo v Lorenzo Giustino [182] | 6-7,6-7 | |
| ATP Gstaad Qual | 07/22 11:50 | 45 | [409] Yann Marti v Lorenzo Giustino [182] | 4-6,7-6,2-6 | |
| Challenger San Benedetto | 07/18 14:40 | 25 | [182] Lorenzo Giustino v Carlos Taberner [301] | 3-6,5-7 | |
| Challenger Perugia | 07/11 09:00 | 25 | [168] Lorenzo Giustino v Gleb Sakharov [205] | 6-7,2-6 | |
| Challenger Marburg | 07/03 11:30 | 25 | [299] Sorgi, Joao Pedro v Lorenzo Giustino [168] | 6-7,6-3,7-6 | |
| Wimbledon Qual | 06/26 10:00 | 44 | [119] Darian King v Lorenzo Giustino [168] | 6-4,6-0 | |
| Lyon, France | 06/12 16:00 | 25 | [167] Lorenzo Giustino v Casper Ruud [112] | 4-6,0-6 | |
| Challenger - Prostejov | 06/06 09:00 | 25 | [175] Lorenzo Giustino v Souza, Joao Olavo [140] | 5-7,7-6,3-6 | |
| Challenger - Vicence | 06/03 11:30 | 28 | [175] Lorenzo Giustino v Laslo Djere [135] | 4-6,6-2,3-6 | |
| Challenger - Vicence | 06/02 09:30 | 27 | Munoz-De la Nava, Daniel v Lorenzo Giustino | 6-3,3-6,2-6 |
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.