Valentinus is a Roman masculine given name derived from the Latin word "valens" meaning "healthy, strong". It may refer to:

People Churchmen Pope Valentine (died 827) Saint Valentine, 3rd century Christian saint Valentinus (Gnostic) (died c. 150), early Christian gnostic theologian Valentinus Paquay (1828–1905), Friar Minor Valentinus Smalcius (1572–1622), German Socinian theologian

Emperors and pretenders Valentinus (rebel), 4th-century Roman exile who attempted a conspiracy in Roman Britain Valentinus (usurper) (died 644), Byzantine general and usurper, father of empress Fausta

Scholars Basilius Valentinus, 15th century monk from Erfurt who may have described bismuth Valentinus Lublinus (16th-century–16th-century), 16th-century Polish physician and editor Valentinus Otho (died 1603), German mathematician and astronomer Valentinus Nabodus (1523–1593), German mathematician, astronomer and astrologer

Biology Anacyclus valentinus, a species of aster Ischnocolus valentinus, a small, old-world tarantula Squalius valentinus, a species of freshwater fish in the carp family Cyprinidae

See also Valentin, given name Valentina (given name), the feminine of Valentinus Valentine (disambiguation) Valentinian (disambiguation) Bálint, the Hungarian version