The 37-year-old admitted in written documents to abusing his wife and was left out of the Giants' game against Los Angeles Rams in London earlier this week.
It has now been announced that Brown, who has spent the past three years with the New Jersey-based outfit, is a free agent after his side finally took the decision to cut all ties.
Giants co-owner John Mara told ESPN: "We believed we did the right thing at every juncture in our relationship with Josh. Our beliefs, our judgements and our decisions were misguided. We accept that responsibility. We hope that Josh will continue to dedicate himself to rehabilitation, and to becoming a better person and father.
"We will continue to support him in his efforts to continue counselling, and we hope that Josh and his family can find peace and a positive resolution. We have great respect and feel strongly about our support for the good people who work tirelessly and unconditionally to aid the victims of domestic violence and who bring awareness to the issue."
Brown had earlier released a statement stressing that he had "never struck" his now ex-wife, adding that "abuse comes in many forms".