| Tony van Diepen | |
| Birth Date: | 17 April 1996 |
| Birth Place: | Heerhugowaard, Netherlands |
| Height: | 1.83 m |
| Weight: | 68 kg |
| Country: | Netherlands |
| Sport: | Athletics |
| Event: | 400 metres, 800 m |
| Club: | Haag Atletiek |
| Coach: | Grete Koens Laurent Meuwly[1] |
Tony van Diepen (pronounced as /nl/; born 17 April 1996) is a Dutch track and field athlete competing in the 400 and 800 metres. He won the bronze medal in the 400 m at the 2019 European Indoor Championships and silver at the 2021 European Indoor Championships. Van Diepen earned five medals with Dutch 4 × 400 m relays, either men's or mixed, at major championships, including silver for the men's relay at the 2020 Tokyo Olympics.
He took four national titles.
| 2013 | European Junior Championships | Rieti, Italy | 24th (h) | 800 m | 1:53.44 | |
| 2014 | World Junior Championships | Eugene, OR, United States | 16th (sf) | 800 m | 1:50.86 | |
| 2015 | European Junior Championships | Eskilstuna, Sweden | 19th (sf) | 800 m | 1:53.60 | |
| 2017 | European Indoor Championships | Belgrade, Serbia | 22nd (h) | 400 m | 48.57 | |
| European U23 Championships | Bydgoszcz, Poland | 16th (h) | 800 m | 1:50.38 | ||
| 2018 | European Championships | Berlin, Germany | 9th (h) | 4 × 400 m relay | 3:04.93 | |
| 2019 | European Indoor Championships | Glasgow, United Kingdom | 3rd | 400 m | 46.13 | |
| World Relays | Yokohama, Japan | 5th (B) | 4 × 400 m relay | 3:05.15 | ||
| 2021 | European Indoor Championships | Toruń, Poland | bgcolor=silver | 2nd | 400 m | 46.25 |
| bgcolor=gold | 1st | 4 × 400 m relay | 3:06.06 | |||
| World Relays | Chorzów, Poland | bgcolor=gold | 1st | 4 × 400 m relay | 3:03.45 | |
| Olympic Games | Tokyo, Japan | 23rd (h) | 800 m | 1:46.03 | ||
| bgcolor=silver | 2nd | 4 × 400 m relay | 2:57.18 | |||
| 2022 | World Indoor Championships | Belgrade, Serbia | 19th (h) | 800 m | 1:49.80 | |
| 3rd | 4 × 400 m relay | 3:06.90 | ||||
| World Championships | Eugene, OR, United States | 18th (sf) | 800 m | 1:46.70 | ||
| bgcolor=silver | 2nd | 4 × 400 m mixed | 3:09.90 | |||
| European Championships | Munich, Germany | 6th (sf) | 800 m | 1:47.64 | ||
| 2023 | European Indoor Championships | Istanbul, Turkey | 14th (h) | 800 m | 1:48.50 | |
| 2024 | World Indoor Championships | Glasgow, United Kingdom | 3rd | 4 × 400 m relay | 3:04.25 |