| Sebastián Masdeu | |
| Full Name: | Sebastián Masdeu Menasanch |
| Birth Date: | 1889 |
| Birth Place: | Tarragona, Spain |
| Death Date: | 5 January 1964 (aged 74-75) |
| Death Place: | Barcelona, Spain |
| Discipline: | Road |
| Role: | Rider |
Sebastián Masdeu Menasanch (1889 – 5 January 1964) was a Spanish cyclist, who won the first edition of the Volta a Catalunya in 1911.[1]