| French Open - Dames | 05/24 15:20 | 15 | [257] Petra Marcinko v Clara Tauson [126] | 2-6,1-6 | |
| French Open - Dames | 05/23 13:30 | 14 | [257] Petra Marcinko v Katherine Sebov [141] | 3-6,6-0,6-2 | |
| ITF W60 - Zagreb | 05/10 08:00 | 26 | [232] Zeynep Sonmez v Petra Marcinko [234] | 6-4,7-5 | |
| ITF W60 - Zagreb | 05/09 07:55 | 25 | [234] Petra Marcinko v Reka-Luca Jani [147] | 6-3,4-6,7-5 | |
| ITF W25 - Osijek | 04/28 09:00 | 27 | [276] Dominika Salkova v Petra Marcinko [214] | 0-6,6-1,6-4 | |
| ITF W25 - Osijek | 04/27 09:00 | 26 | Antonia Schmidt v Petra Marcinko | 1-6,3-6 | |
| ITF W25 - Osijek | 04/26 08:00 | 25 | [450] Zongyu Li v Petra Marcinko [214] | 2-6,1-6 | |
| Billie Jean King Cup | 04/13 06:50 | 1 | [333] Caijsa W Hennemann v Petra Marcinko [211] | 6-4,7-5 | |
| Billie Jean King Cup | 04/11 08:00 | 1 | [211] Petra Marcinko v Lia Karatancheva [375] | 6-4,3-6,3-6 | |
| Billie Jean King Cup | 04/10 08:30 | 1 | Petra Marcinko v Johanne C Svendsen | 2-6,7-5,7-5 | |
| ITF - W40 Split | 04/06 08:50 | 27 | [213] Petra Marcinko v Tara Wurth [170] | 6-7,6-7 | |
| ITF - W40 Split | 04/05 09:50 | 26 | [213] Petra Marcinko v Tena Lukas [229] | 6-2,6-3 | |
| ITF - W40 Split | 04/04 07:50 | 25 | [213] Petra Marcinko v Gergana Topalova [306] | 6-1,6-3 | |
| WTA - Indian Wells | 03/07 02:35 | 14 | [66] Varvara Gracheva v Petra Marcinko [161] | 7-6,6-4 | |
| ITF W60 - Arcadia | 03/04 19:00 | 28 | [107] Sara Errani v Petra Marcinko [173] | 6-0,3-6,7-5 | |
| ITF W60 - Arcadia | 03/03 21:40 | 27 | Petra Marcinko v Megan McCray | 6-2,6-2 | |
| ITF W60 - Arcadia | 03/02 19:00 | 26 | [173] Petra Marcinko v Hanna Chang [335] | 6-4,6-3 | |
| ITF W60 - Arcadia | 03/01 19:00 | 25 | [173] Petra Marcinko v Mana Ayukawa [268] | 6-2,6-3 | |
| ITF W60 - Orlando | 02/09 17:35 | 26 | [179] Petra Marcinko v Caroline Dolehide [188] | 3-6,2-6 | |
| ITF W60 - Orlando | 02/08 17:25 | 25 | [179] Petra Marcinko v Francesca Curmi [395] | 6-2,6-7,6-2 | |
| ITF W60 Rome, GA | 02/02 18:10 | 26 | [296] Andrea Lazaro Garcia v Petra Marcinko [182] | 4-6,7-5,6-3 | |
| ITF W60 Rome, GA | 02/01 15:00 | 25 | Ganna Poznikhirenko v Petra Marcinko | Retired | |
| Australian Open - Dames | 01/11 00:40 | 15 | [187] Petra Marcinko v Coco Vandeweghe [140] | 4-6,2-6 | |
| Australian Open - Dames | 01/09 05:15 | 14 | [187] Petra Marcinko v Mona Barthel [222] | 6-2,6-4 | |
| ITF - W25 Sharm El Sheikh | 11/18 10:45 | 27 | Ekaterina Shalimova v Petra Marcinko | 6-4,6-3 | |
| ITF - W25 Sharm El Sheikh | 11/17 11:30 | 26 | [440] Giulia G-Monticone v Petra Marcinko [194] | 3-6,4-6 | |
| ITF - W25 Sharm El Sheikh | 11/16 12:25 | 25 | Mananchaya Sawangkaew v Petra Marcinko | 3-6,6-7 | |
| Billie Jean King Cup | 11/12 14:40 | 64 | Petra Marcinko v Eva Lys | Cancelled | |
| Billie Jean King Cup | 11/12 09:00 | 64 | [194] Petra Marcinko v Anna-Lena Friedsam [145] | 4-6,1-6 | |
| Billie Jean King Cup | 11/11 16:50 | 64 | [194] Petra Marcinko v Jule Niemeier [61] | 6-3,6-2 |