French sister Nathalie Becquart will be the first woman to be appointed to the position and will be entitled to vote at the synod.
This puts her in a position to help make important decisions in the Catholic Church, according to Vatican News, the Holy See’s official press website.
The Synod advises the Roman Pontiff, including many controversial topics, such as divorce.
Pope Francis appointed Becquart, along with Fr. Luis Marn de San Martin as the last undersecretary.
Cardinal Mario Grech, who heads the Synod, told Vatican News that a “door has been opened” to the possibility of more women voting.
“During the last Synods, several synod fathers have emphasized the need for the whole Church to reflect on the place and role of women in the Church,” said Grech.
“Even Pope Francis has repeatedly stressed the importance of women becoming more involved in the discernment and decision-making processes in the Church. In recent synods, the number of women participating as experts or auditors has increased.
“With the appointment of Sr. Nathalie Becquart and the possibility for her to participate with the right to vote, a door opened. We will then see that other steps can be taken in the future, ”added Grech.