Birth Name: William Gregory Magnussen
Place of Birth: Woodhaven, Queens, New York City, New York, U.S.
Date of Birth: April 20, 1985
Billy Magnussen is an American actor and musician.
His maternal grandparents were ethnic Lithuanian immigrants (born in Latvia). The surname Magnussen can be either Danish or Norwegian.
Billy’s paternal grandmother is named Ruth D.
Billy’s maternal grandfather was Algimantas Siemaška (the son of Jonas Siemaška and Paulina Švaigždytė/Svagzdyte).
Billy’s maternal grandmother is Otilija Meškauskaitė/Meskauskas (the daughter of Mikalojus Meškauskas and Stefanija Beinorytė/Beinoritė). Mikalojus was the son of Jonas Meškauskas and Paulina Student. Stefanija was the daughter of Beinoris.
Source: Genealogy of Billy Magnussen (focusing on his mother’s side) – http://www.geni.com