| Fullname: | Leon Henry Vaessen |
| Position: | Half-back |
| Birth Date: | 8 November 1940 |
| Birth Place: | New Cross, England |
| Youthyears1: | ?–1958 |
| Youthclubs1: | Chelsea |
| Years1: | 1958–1961 |
| Years2: | 1961–1963 |
| Years3: | 1963–1965 |
| Years4: | 1965–? |
| Clubs1: | Millwall |
| Clubs2: | Gillingham |
| Clubs3: | Dover |
| Clubs4: | Crawley Town |
| Caps1: | 26 |
| Goals1: | 2 |
| Caps2: | 29 |
| Goals2: | 0 |
Leon Henry Vaessen (born 8 November 1940) was an English professional footballer of the 1950s and 1960s. He made over 50 appearances in The Football League.
Born in New Cross, he joined Chelsea as a youngster, but was not offered a professional contract. In January 1958 he signed for Millwall and went on to make 26 Football League appearances for the "Lions",[1] but never established himself as a regular starter. At the end of the 1960–61 season, he was transferred to Gillingham. He was initially a regular in the team, but fell out of favour, playing just once in the 1962–63 season,[2] before being sold to Dover for a fee of £500. His last known club was Crawley Town.[3]
His mother was English and his father was Dutch.[4] His son Paul played for Arsenal but was forced to retire due to injury and fell into a life of crime and drug addiction before dying at the age of 39 in 2001.[5]