Harry Nilsson's grandfather, Charles Harry Nilsson was born on September 11, 1894, in New York, New York. His father was Carl Emanuel Nilsson and his mother the former Augusta Wilhelmine Adele Rolle.
On January 31, 1915, he married Catherine Beatrice Robb.
They had several children.
- Mona Nilsson born July 20, 1915.
- Harry Edward Nilsson, Jr. born on January 20, 1917.
- Beatrice Nilsson born in 1919.
- Melba Catherine Nilsson born April 13, 1923.
- Eileen Evelyn Nilsson born May 21, 1924.
Charles Harry Nilsson died in September of 1962.