James Chadwick's father was Joseph Chadwick. He started a laundry business elsewhere which forced James to live with his grandmother as his mother, Anne Mary Knowles, was not around either. Chadwick was a shy child who was quite immature and didn't get along with other children very easily.
With all of his success in being a scientist, Chadwick had plenty of money and in 1925 he married a lady by the name of Aileen Stewart-Brown, together they had twin daughters, Joana and Judith Chadwick.