| Spain Masters | 02/19 15:00 | 5 | Kai Schaefer v Misha Zilberman | W | 2-1 | |
| Európai csapatbajnokság | 02/14 14:00 | - | Viktor Axelsen v Kai Schaefer | L | 2-0 | |
| Syed Modi Int. | 11/27 11:40 | 5 | Kwang Hee Heo v Kai Schaefer | L | 2-0 | |
| Scottish Open | 11/21 17:30 | 5 | Eetu Heino v Kai Schaefer | L | 2-0 | |
| Irish Open | 11/15 10:30 | 3 | Kai Schaefer v Pablo Abian | L | 0-2 | |
| Irish Open | 11/14 19:45 | 4 | Max Weisskirchen v Kai Schaefer | W | 0-2 | |
| Irish Open | 11/14 12:30 | 5 | Kai Schaefer v Yu Hsien Lin | W | 2-0 | |
| SaarLorLux Open | 10/30 17:20 | 5 | Rahul Bharadwaj B.M v Kai Schaefer | L | 2-0 | |
| Dutch Open | 10/10 13:40 | 4 | Felix Burestedt v Kai Schaefer | L | 2-1 | |
| Dutch Open | 10/09 14:05 | 5 | Kai Schaefer v Sourabh Verma | W | 2-1 | |
| Dutch Open | 10/08 15:15 | 6 | Kai Schaefer v Pablo Abian | W | 2-0 | |
| Belgian Int. | 09/13 17:10 | 2 | Kai Schaefer v Victor Svendsen | L | 1-2 | |
| Belgian Int. | 09/13 09:25 | 3 | Kai Schaefer v Ygor Coelho | W | 2-1 | |
| Belgian Int. | 09/12 17:30 | 4 | Kai Schaefer v Toby Penty | W | 2-1 | |
| Belgian Int. | 09/12 13:30 | 5 | Kai Schaefer v Felix Burestedt | W | 2-0 | |
| Kharkiv Int. | 09/06 07:30 | 5 | Eetu Heino v Kai Schaefer | L | 2-0 | |
| Világbajnokság | 08/19 08:40 | 6 | Guangzu Lu v Kai Schaefer | L | 2-0 | |
| US Open | 07/10 23:30 | 5 | Kai Schaefer v Xiaodong Sheng | L | 0-2 | |
| Canada Open | 07/03 20:20 | 5 | Kai Schaefer v Lucas Claerbout | L | 0-2 | |
| Spanish Int. | 06/14 08:00 | - | Kai Schaefer v Toby Penty | L | 0-2 | |
| Spanish Int. | 06/13 12:45 | - | Luis Enrique Penalver v Kai Schaefer | W | 0-2 | |
| Azerbaijan Int. | 06/08 14:00 | - | Rasmus Gemke v Kai Schaefer | L | 2-1 | |
| Azerbaijan Int. | 06/08 07:30 | - | Luis Enrique Penalver v Kai Schaefer | W | 0-2 | |
| Azerbaijan Int. | 06/07 12:00 | - | Giap Chin Goh v Kai Schaefer | W | 1-2 | |
| Sudirman Cup | 05/22 04:00 | - | Kai Schaefer v Jason Anthony Ho-Shue | W | 1-0 | |
| Sudirman Cup | 05/19 11:00 | - | Kai Schaefer v Misha Zilberman | L | 0-2 | |
| Denmark Int. | 05/12 09:00 | - | Kai Schaefer v Hans-Kristian Vittinghus | L | 0-2 | |
| Denmark Int. | 05/11 14:30 | - | Lucas Claerbout v Kai Schaefer | W | 0-2 | |
| Denmark Int. | 05/11 08:30 | - | Rasmus Gemke v Kai Schaefer | W | 1-2 | |
| Denmark Int. | 05/10 13:40 | - | Kai Schaefer v Lakshya Sen | W | 2-1 |
Kai Hendrik Schäfer (born 13 June 1993) is a German badminton player. He competed at the 2020 Tokyo Olympics.