Falernum is a sweet syrup used in Tropical and Caribbean drinks. It contains flavors of almond, ginger and/or cloves, and lime, and sometimes vanilla or allspice. It is used in cocktails in a manner similar to orgeat syrup or drunk on the rocks. The syrup form can be alcoholic or non-alcoholic. The consistency is thick, the color can be white to light amber, and it may be clear or translucent.

Falernum owes its name to the renowned ancient Roman wine Falernian, known as Falernum in Latin.

Some reports have the origination of Falernum dated back to the 1700s, but the earliest known reference in bar manuals seems to be the 1930s.