Meghan Markle has reportedly been baptised and confirmed in the Church of England at a private ceremony led by the Archbishop of Canterbury.
The American actress is said to have been formally introduced to the Anglican faith as her wedding to Prince Harry draws closer.
The Daily Mail reported the 45-minute service took place with her husband-to-be in attendance at the Chapel Royal on Tuesday evening.
They are due to wed at St George's Chapel in Windsor Castle on May 19.
The Queen, Harry's grandmother, is the head of the Church of England.
While the monarch is reported not to have attended the ceremony, guests included the Prince of Wales, according to the Daily Mail.
The Archbishop of Canterbury, Justin Welby, led the service, the newspaper said. He will marry the couple in May.
The Daily Mail said holy water from the River Jordan was poured on the 36-year-old's head as part of the ritual.
The news follows reports at the weekend that Ms Markle, who was a member of the Protestant faith and went to a Catholic high school, was due to convert imminently.
Her mother, Doria Ragland, is Protestant and her father, Thomas Markle, is Episcopalian.
Shortly before her wedding, the Duchess of Cambridge was confirmed.
Kate's husband, the Duke of Cambridge, as a future king, will one day be Supreme Governor of the Church of England.
A spokesman for Kensington Palace said: "We are not commenting."
