Assange and Moris made their relationship public in April 2020 and had applied to prison authorities for permission to wed.
They threatened legal action against the prison governor and Justice Secretary Dominic Raab, accusing them of trying to prevent the marriage from taking place.
“Mr. Assange’s application was received, considered and processed in the usual way by the prison governor, as for any other prisoner,” the Prison Service said Thursday.
No date has yet been set for the wedding.
U.S. prosecutors have indicted Assange on 17 espionage charges and one charge of computer misuse over WikiLeaks’ publication of thousands of leaked military and diplomatic documents a decade ago.