| ITF W25 Troisdorf | 05/31 09:00 | 25 | Gerlach, Katharina v Angelina Wirges | 6-4,4-6,2-6 | |
| ITF W25 Troisdorf | 05/29 14:30 | 54 | Gerlach, Katharina v Hering, Katharina | 7-5,6-4 | |
| ITF W25 Troisdorf | 05/28 10:00 | 54 | Gerlach, Katharina v Oceanne Lopez | 6-0,6-2 | |
| ITF W25 Santa Margherita | 10/19 12:00 | 25 | [293] Nuria Brancaccio v Gerlach, Katharina [261] | 6-4,6-7,6-2 | |
| ITF W25 Santa Margherita | 10/13 12:00 | 25 | [407] Amina Anshba v Gerlach, Katharina [267] | 6-3,5-7,6-4 | |
| ITF W25 Otocec | 10/01 08:00 | 27 | [265] Gerlach, Katharina v Nina Potocnik [303] | 6-3,3-6,2-6 | |
| ITF W25 Otocec | 09/30 07:00 | 26 | [265] Gerlach, Katharina v Jessie Aney [391] | 7-6,6-2 | |
| ITF W25 Otocec | 09/28 08:20 | 25 | [265] Gerlach, Katharina v Christina Rosca [207] | 6-2,3-6,10-3 | |
| ITF W60 Collonge-Bellerive | 08/31 13:15 | 25 | [251] Gerlach, Katharina v Matilde Paoletti [490] | 4-6,4-6 | |
| US Open Women | 08/23 15:00 | 14 | [110] Chloe Paquet v Gerlach, Katharina [250] | 6-7,6-4,6-3 | |
| ITF W60 Cordenons | 07/28 12:30 | 27 | [106] Panna Udvardy v Gerlach, Katharina [229] | 6-3,7-5 | |
| ITF W60 Cordenons | 07/27 09:00 | 26 | [286] Sada Nahimana v Gerlach, Katharina [229] | 6-3,4-6,1-6 | |
| ITF W60 Cordenons | 07/26 08:30 | 25 | [239] Lina Gjorcheska v Gerlach, Katharina [229] | 2-6,6-4,3-6 | |
| ITF W25 Perugia | 07/20 09:00 | 25 | Gerlach, Katharina v Ines Ibbou | 4-6,3-6 | |
| ITF W100 Versmold | 07/06 08:00 | 25 | Julia Grabher v Gerlach, Katharina | Cancelled | |
| Wimbledon Women | 06/21 10:00 | 14 | [233] Gerlach, Katharina v Timea Babos [294] | 1-6,1-6 | |
| ITF W60 Caserta | 06/09 18:20 | 26 | [225] Gerlach, Katharina v Nuria Brancaccio [426] | 7-5,0-6,4-6 | |
| ITF W60 Caserta | 06/08 16:00 | 25 | [94] Clara Burel v Gerlach, Katharina [225] | 5-7,6-2,4-6 | |
| ITF W60 Grado | 05/24 15:20 | 25 | [117] Ylena In-Albon v Gerlach, Katharina [234] | 6-1,6-2 | |
| French Open Women | 05/18 12:10 | 15 | [219] Yuki Naito v Gerlach, Katharina [232] | 2-6,6-3,6-3 | |
| French Open Women | 05/17 10:50 | 14 | [232] Gerlach, Katharina v Vandeweghe, Coco [129] | 7-6,6-4 | |
| ITF - W100 Wiesbaden | 05/03 12:00 | 25 | [217] Gerlach, Katharina v Rebecca Peterson [76] | 2-6,4-6 | |
| ITF W60 Chiasso | 04/20 08:00 | 25 | [218] Gerlach, Katharina v Erika Andreeva [252] | 6-7,6-3,3-6 | |
| ITF W25 Oeiras | 04/16 12:30 | 28 | Diana Shnaider v Gerlach, Katharina | 6-4,6-2 | |
| ITF W25 Oeiras | 04/15 10:00 | 27 | [223] Gerlach, Katharina v Jessica Bouzas Maneiro [327] | 6-1,6-4 | |
| ITF W25 Oeiras | 04/14 13:00 | 26 | [223] Gerlach, Katharina v Yerolymos, Margot [378] | 6-4,7-5 | |
| ITF W25 Oeiras | 04/13 14:05 | 25 | [223] Gerlach, Katharina v Parres Azcoitia, Olga [354] | 6-0,6-1 | |
| ITF W80 Oeiras | 04/07 10:30 | 26 | [107] Viktoriya Tomova v Gerlach, Katharina [226] | 6-1,7-6 | |
| ITF W80 Oeiras | 04/06 13:10 | 25 | [226] Gerlach, Katharina v Diatchenko, Vitalia [108] | 6-0,7-5 | |
| ITF W80 Oeiras | 04/04 11:00 | 54 | [226] Gerlach, Katharina v Jessica Bouzas Maneiro [330] | 4-6,6-0,14-12 |