Lemmens is a Dutch patronymic surname derived from "Lambert's son". The name is particularly popular in Belgian Limburg where it is the ninth most common last name. Notable people with the surname include:
Alfons Lemmens (1919–2013), Dutch footballer
An Lemmens (born 1980), Belgian presenter
Erwin Lemmens (born 1976), Belgian professional soccer player
Gertrude Lemmens (1914–2000), Dutch Roman Catholic sister and missionary
Helen Lemmens (1834–1906), English soprano, wife of Jacques-Nicolas Lemmens
Jacques-Nicolas Lemmens (1823–1881), Flemish composer and organist
Jean-Nicolas Lemmens (1850–1897), Dutch Catholic priest and Canadian bishop
Leon Lemmens (born 1954), Belgian Roman Catholic auxiliary bishop
Stacy Lemmens (1998–2006), Belgian murder victim
Salesius Lemmens (1904–1942), Dutch Apostolic Prefect of the Order of Friars Minor
Lemmen:
Celina Lemmen (born 1985), Dutch swimmer
Georges Lemmen (1865–1916), Belgian neo-impressionist painter