The Ollongren family, also spelled ÃÂ llongren is a Finnish noble family.
The progenitor of the family, Olof, owned an estate of Pepot (Peippola) in Porvoon maalaiskunta. His son Nils Olofsson was a Nimismies 1480.
The family was immatriculated into Swedish House of Nobility 1625 under number 115, and it got surname ÃÂ llongren i Finland from its coat of arms, displaying two oak tree branches with acorns (modern swedish: ekollon).
The family became extinct in Finland 1806, but continued in Russia. The surname has been made known in Netherlands by astronomer Alexander Ollongren and politician Kajsa Ollongren.