Yes, Isaac Newton had three siblings. He was born on January 4, 1643, in Woolsthorpe, Lincolnshire, England, and was the only son of Isaac Newton Sr. and Hannah Ayscough Newton. However, his father died three months before he was born, and his mother remarried when he was three years old, leaving him in the care of his maternal grandmother while she moved away with her new husband.
Newton’s siblings included two half-sisters, Mary and Hannah, and a half-brother, Benjamin. Due to the nature of his early life and the family dynamics, he was not particularly close to them. After his mother’s remarriage, he had limited contact with his family, which likely influenced his later solitary and focused nature in both his personal and professional life.