Fontaine is of French origin, meaning "fountain". It's a surname that has been used as a given name in recent years. In literature, it's notably the last name of French novelist Victor Hugo's daughter and her famous works such as "Les Misérables". As a given name, Fontaine is unisex but has seen more usage for females in recent decades. It's often associated with the refreshing and life-giving qualities of its namesake object.
"The name Fontaine experienced peaks in popularity around the late 1950s to early 1960s with nine or more births per year during those periods. However, it has since stabilized with five births being the norm in most years since the 1970s."