William Nichols was a printer. He married Mary Ann Nichols in 1864. They had five children together, the last of whom was born in 1879, but the marriage was an unhappy one and had dissolved by 1881. The reasons for this dissolution is unclear. Nichols himself suggested that it was because of his wife's dissolute ways, while her father, Edward Walker, said that it was because Nichols had engaged in an affair with the midwife who had delivered his last child. Nichols denied these allegations. One of the children, Edward Nichols, sided with his mother and moved in with his grandfather. The other children remained in the care of their father. Nichols supported Mary Ann with court-mandated payments until 1882, when he claimed that she had begun engaging in prostitution and thus he had no legal obligation to continue supporting her.
When she was murdered at the end of August of 1888 he went to the morgue to identify her body. When he viewed it he reportedly forgave her for the wrongs she had done him in her life. He attended her funeral. No other documentation exists on his life