Proctor was originally from Ipswich, where he and his father before him had a farm of considerable value. In 1666 he moved to Salem, where he worked on a farm, part of which he later bought. Proctor seems to have been an enormous man, very large framed, with great force and energy. Although an upright man, he seems to have been rash in speech, judgment, and action. It was his unguarded tongue that would eventually lead to his death. From the start of the outbreak of witchcraft hysteria in Salem, Proctor had denounced the whole proceedings and the afflicted girls as a scam. When his wife was accused and questioned, he stood with her throughout the proceedings and staunchly defended her innocence. It was during her questioning that he, too, was named a witch. Proctor was the first male to be named as a witch in Salem. In addition, all of his children were accused. His wife Elizabeth, and Elizabeth's sister and sister-in-law, also were accused witches. Although tried and condemned, Elizabeth avoided execution because she was pregnant.

Mary Warren, the twenty-year-old maid servant in the Proctor house--who herself would later be named as a witch--accused Proctor of practicing witchcraft. It is believed by some sources that when Mary first had fits Proctor, believing them to be fake, would beat her out of them. Even if it didn't actually beat her, he certainly threatened beatings and worse if she didn't stop the fits. It was this type of outspoken criticism of the afflicted that caused Proctor to be accused.

Proctor was tried on August 5 and hanged on the 19th. While in prison on July 23, Proctor wrote a letter to the clergy of Boston, who were known to be uneasy with the witchcraft proceedings. In his letter he asked them to intervene to either have the trials moved to Boston or have new judges appointed. After the trial and execution of Rebecca Nurse, the prospects of those still in prison waiting trial were grim. If a person with a reputation as untarnished as hers could be executed, there was little hope for any of the other accused, which is why Proctor made his request. With the present judges, who were already convinced of guilt, the trial would just be a formality. In response to Proctor's letter, in which he describes certain torture that was used to elicit confessions, eight ministers, including Increase Mather, met at Cambridge on August 1. Little is known about this meeting, except that when they had emerged, they had drastically changed their position on spectral evidence. The ministers decided in the meeting that the Devil could take on the form of innocent people. Unfortunately for Proctor, their decision would not have widespread impact until after his execution.

Proctor pleaded at his execution for a little respite of time. He claimed he was not fit to die. His plea was, of course, unsuccessful. In seventeenth-century society, it would not have been uncommon for a man so violently tempered as Proctor to feel that he had not yet made peace with his fellow man or his God. In addition, it is thought that he died inadequately reconciled to his wife, since he left her out of the will that he drew up in prison. Proctor's family was given 150 pounds in 1711 for his execution and his wife's imprisonment.