The name Fontenay was recorded in the Middle Ages as Fontanetum, meaning "the springs", from Medieval Latinfontana ("natural spring").
The commune was known alternatively as Fontenay-les-Bois (meaning "Fontenay by the woods"), Fontenay-sur-le-Bois (meaning "Fontenay over the wood"), or Fontenay-sous-Bois (meaning "Fontenay under wood"), but eventually in the early 19th century the latter name of Fontenay-sous-Bois became the only name. The wood referred to in the name of the commune is the Bois de Vincennes.
The Rosettes fountain was lost during World War II. Years later, it was found by chance in a market in the South of France; the town of Fontenay-sous-Bois recovered it, and re-installed it in the place where it can be seen today.
¹This group is made up largely of former French settlers, such as pieds-noirs in Northwest Africa, followed by former colonial citizens who had French citizenship at birth (such as was often the case for the native elite in French colonies), and to a lesser extent foreign-born children of French expatriates. Note that a foreign country is understood as a country not part of France as of 1999, so a person born for example in 1950 in Algeria, when Algeria was an integral part of France, is nonetheless listed as a person born in a foreign country in French statistics.
²An immigrant is a person born in a foreign country not having French citizenship at birth. Note that an immigrant may have acquired French citizenship since moving to France, but is still considered an immigrant in French statistics. On the other hand, persons born in France with foreign citizenship (the children of immigrants) are not listed as immigrants.
Jean-François Voguet, mayor from 2001 to 2014, ordered the expulsion of people living in a house belonging to the city. The mayor is now part of the few PCF mayors who practice the expulsion of squatters.