Lalonde or LaLonde (US spelling) is a surname. Notable people with the surname include:
It means literally "from a place called La Londe". There are more or less 100 places called La Londe in Normandy, France, including the commune La Londe in the Seine-Maritime department. In Old Norman(-French) it meant "grove, wood", itself from Old Norse lundr (accusative lund) "grove" + French feminine definite article la.
Variant forms include Delalonde, Delalondre.
The French surnames Delalande, Lalande (Gasconic Lalanne) are unrelated to it, but from one of the numerous French place-names called La Lande, lande being a French word that means "moor", itself from Gaulish (Celtic) *landa.