There is no Saint Valentino. However, if you meant to write Valentine, there are several saints by that name. The most famous is St. Valentine of Rome who was born sometime early in the third century.
There is no saint named Valentino but there are several named Valentinus or Valentine in English.
Valentino Mastrozzi was born in 1729.
Valentino Fioravanti was born in 1764.
Valentino Argento was born in 1888.
Frank Valentino was born in 1907.
Valentino Degani was born in 1905.
Valentino Castellani was born in 1940.
Eligio Valentino was born in 1925.
Jim Valentino was born in 1952.
Valentino Siani was born in 1595.
Valentino Braitenberg was born in 1926.
Valentino Gasparella was born in 1935.