The Pope has appointed a woman as an undersecretary to the Synod of Bishops for the first time.
Sister Nathalie Becquart, who is from France, will have voting rights in the body, which advises the pontiff and debates some of the most controversial issues in the Roman Catholic Church.
Ms Becquart has worked with the synod as a consultant since 2019.
The body’s secretary-general, Cardinal Mario Grech, said the appointment showed that “a door has opened”.
He noted that the decision reflects the Pope’s desire “for a greater participation of women in the process of discernment and decision-making in the church”.
The BBC’s John McManus says the move is not a precursor to ordaining women as priests, although some opponents may regard it as a further step in that direction.
Luis Marín de San Martín, a priest from Spain, was also named as a new undersecretary of the synod.
In recent years, the Synod of Bishops has debated topics of doctrine including the treatment of divorced and married Catholics.
The news comes less than a month after Pope Francis formally changed the law in the Church to allow women to administer communion and serve at the altar, although the decree stressed that ordained priesthood would remain open to men only.
Last year, meanwhile, the pontiff appointed six women to the council which oversees the Vatican’s finances.
Pope Francis has formally changed the law in the Roman Catholic Church, allowing women to administer communion and serve at the altar.
But the ordained priesthood will still be the preserve of men, he stressed in the decree. It is official recognition of roles already performed by women in some Catholic services, especially in Western countries.
The Pope said women were making a “precious contribution” to the Church.
The announcement is expected to force conservative Church leaders to accept greater involvement of women in the liturgy.
On the more reformist wing of the Church, Pope Francis has tried to present a more welcoming image through his rhetoric, the BBC’s Mark Lowen reports from Rome.
But last year, after a synod to decide whether to allow women to become deacons able to preside over some Church services, the Pope refused to make the change, frustrating some who had hoped for more fundamental reform during his pontificate.
The Pope changed a clause in canon law from “lay men” to “lay persons”, specifying that they can perform “the ministries of lector and acolyte” in Catholic services.
His decree, called a Spiritus Domini, was accompanied by a letter explaining “the urgency... to rediscover the co-responsibility of all of the baptised in the Church, and the mission of the laity in a particular way”.
A lector in the Catholic Church can recite prayers and sacred texts such as psalms during Mass and other services, but gospel readings are done by the priest or deacon.