Fulmen was a Spanish automotive brand founded in 1921 by Ernesto Rodriguez Franco in Barcelona. The company specialized in the production of cyclecars, a type of lightweight vehicle that typically featured minimalistic design and construction.

The brand was short-lived, and its production did not extend beyond a few years. Despite its brief existence, Fulmen contributed to the early automotive landscape in Spain. Rodriguez Franco, in addition to his work with Fulmen, was known for his contributions to automotive literature, notably as an author of the "Enciclopedia del Automóvil."

The legacy of Fulmen remains limited, primarily due to its ephemeral presence in the automotive market, but it reflects the early 20th-century interest in innovative vehicle designs in Spain.