Meghan Markle will be baptised into the Church of England to please the Queen, despite her Catholic schooling and "Jewish first wedding".
Markle, from Los Angeles, will be both baptised and confirmed as she prepares for her church wedding with Prince Harry, in May.
The bride-to-be is Christian, a member of the Protestant faith who went to a Catholic high school, the Daily Mail reports.
Her mother Doria Ragland is Protestant while her father Thomas Markle is Episcopalian.
However, her first husband, US TV producer Trevor Engelson, was Jewish and the couple tied the knot in a bohemian ceremony at the Jamaica Inn in Ocho Rios, Jamaica.
The wedding lasted four days and in keeping with Jewish traditions, the couple were lifted on chairs as the guests danced in celebration at their reception.
However, their marriage ended in divorce two years later with the couple citing "irreconcilable differences".
Before Markle walks down the aisle with Prince Harry at St George's Chapel, Windsor Castle, she must become a member of the Church of England, of which the Queen is head.
A person wishing to marry in a church is not required to be christened or confirmed but will usually have a link to that church in some way.
In the case of St George's Chapel, this is where Harry was christened.
The decision for Markle to be baptised and confirmed before the wedding will be seen as a nod to the Queen's strong faith and traditions within the monarchy.
Shortly before her wedding, the Duchess of Cambridge was confirmed.
The Duke of Cambridge, as a future king, will one day be Supreme Governor of the Church of England.
Both baptism and confirmation are important parts of the "journey of faith", according to the church's website.
While many people brought up in the faith are baptised as children, adults can undergo the religious ceremony too.
"You are never too old to take this step, and being baptised as an adult is a wonderful experience," the church's website states.
During the ceremony water is usually either poured on the person's head at the font or they may be fully immersed in a special pool within the church.
The service of confirmation can only take place if a person has been baptised, and is about confirming the promises about their faith that were made at the baptism.
Markle could be baptised and confirmed in the same ceremony.