| 2026-09-26 | UFC Fight Night: Rosas Jr. vs. Barcelos | Bantamweight | Alateng Heili def. John Castañeda | Decision (split) (29–28, 28–29, 29–28) | 3 | 5:00 |
| 2026-04-18 | UFC Fight Night: Burns vs. Malott | Catchweight | John Castañeda vs. Mark Vologdin | Draw (majority) (29–27, 28–28, 28–28) | 3 | 5:00 |
| 2025-04-26 | UFC on ESPN: Machado Garry vs. Prates | Featherweight | Chris Gutiérrez def. John Castañeda | Decision (split) (28–29, 29–28, 29–28) | 3 | 5:00 |
| 2024-06-08 | UFC on ESPN: Cannonier vs. Imavov | Bantamweight | Daniel Marcos def. John Castañeda | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2023-11-11 | UFC 295: Procházka vs. Pereira | Catchweight | John Castañeda def. Kang Kyung-ho | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |
| 2023-06-03 | UFC on ESPN: Kara-France vs. Albazi | Bantamweight | John Castañeda def. Muin Gafurov | Decision (unanimous) (29–27, 29–27, 29–27) | 3 | 5:00 |
| 2022-10-01 | UFC Fight Night: Dern vs. Yan | Catchweight | Daniel Santos def. John Castañeda | KO (punches and knee) | 2 | 4:28 |
| 2022-02-05 | UFC Fight Night: Hermansson vs. Strickland | Bantamweight | John Castañeda def. Miles Johns | Technical Submission (arm-triangle choke) | 3 | 1:38 |
| 2021-02-20 | UFC Fight Night: Blaydes vs. Lewis | Bantamweight | John Castañeda def. Eddie Wineland | TKO (punches) | 1 | 4:44 |
| 2020-07-26 | UFC on ESPN: Whittaker vs. Till | Bantamweight | Nathaniel Wood def. John Castañeda | Decision (unanimous) (30–27, 30–27, 30–27) | 3 | 5:00 |