| 2026-08-01 | UFC Fight Night: Medić vs. Rodriguez | Lightweight | Tofiq Musayev def. Ľudovít Klein | TKO (punches) | 2 | 4:07 |
| 2025-10-25 | UFC 321: Aspinall vs. Gane | Lightweight | Ľudovít Klein def. Mateusz Rębecki | Decision (majority) (29–28, 28–27, 28–28) | 3 | 5:00 |
| 2025-05-31 | UFC on ESPN: Gamrot vs. Klein | Lightweight | Mateusz Gamrot def. Ľudovít Klein | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2024-09-28 | UFC Fight Night: Moicano vs. Saint Denis | Lightweight | Ľudovít Klein def. Roosevelt Roberts | Decision (unanimous) (30–27, 29–28, 29–28) | 3 | 5:00 |
| 2024-06-08 | UFC on ESPN: Cannonier vs. Imavov | Lightweight | Ľudovít Klein def. Thiago Moisés | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2024-03-02 | UFC Fight Night: Rozenstruik vs. Gaziev | Lightweight | Ľudovít Klein def. AJ Cunningham | TKO (front kick to the body and punches) | 1 | 4:36 |
| 2023-08-05 | UFC on ESPN: Sandhagen vs. Font | Lightweight | Ľudovít Klein def. Ignacio Bahamondes | Decision (unanimous) (30–27, 29–28, 29–28) | 3 | 5:00 |
| 2023-03-18 | UFC 286: Edwards vs. Usman 3 | Lightweight | Jai Herbert vs. Ľudovít Klein | Draw (majority) (29–27, 28–28, 28–28) | 3 | 5:00 |
| 2022-07-23 | UFC Fight Night: Blaydes vs. Aspinall | Lightweight | Ľudovít Klein def. Mason Jones | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2022-03-05 | UFC 272: Covington vs. Masvidal | Lightweight | Ľudovít Klein def. Devonte Smith | Decision (split) (28–29, 29–28, 30–27) | 3 | 5:00 |
| 2021-10-16 | UFC Fight Night: Ladd vs. Dumont | Featherweight | Nate Landwehr def. Ľudovít Klein | Submission (anaconda choke) | 3 | 2:22 |
| 2021-05-08 | UFC on ESPN: Rodriguez vs. Waterson | Featherweight | Michael Trizano def. Ľudovít Klein | Decision (unanimous) (29–28, 29–28, 30–27) | 3 | 5:00 |
| 2020-09-27 | UFC 253: Adesanya vs. Costa | Catchweight | Ľudovít Klein def. Shane Young | KO (head kick and punches) | 1 | 1:16 |