Seo Chang-wan (born 14 March 1997) is a South Korean modern pentathlete.

He won a bronze medal in the relay at the 2023 World Modern Pentathlon Championships in Bath, England.

[2] In April 2024, he won the UIPM World Cup in Ankara.

[3] He won a silver medal at the 2024 World Modern Pentathlon Championships in the team event, and also won a gold medal in the relay.

[4][5] He competed at the 2024 Summer Olympics in 2024.