Nun versus sister, is there a difference?

Often times you hear or see the terms nun or sister used interchangeably. It might be said that all nuns are sisters, since “sister” is often the title used when referring to a woman religious, but not all sisters are nuns.

If you are familiar with the movie Sister Act, you will hear Whoopi Goldberg reference the sisters as nuns. A lot of what we hear in pop culture references sisters simply as nuns, but there is so much more to the terms sisters and nuns then one might expect.

Sister Adaire Lassonde shares her thoughts on the difference in terms, “Many say we had nuns or sisters for our education, or we are going to visit my aunt who is a nun or sister.” However, there is a difference between the two terms. The School Sisters of Notre Dame (SSND) would be considered sisters based on the definition.

According to A Nun’s Life Ministry website, “A Catholic nun is a woman who lives a contemplative life in a monastery, which is usually cloistered (or enclosed) or semi-cloistered.” Therefore, a Catholic nun would be a woman who lives a more solitary life filled with prayer and quiet, contemplation and who would not typically be involved within the larger community. 

As for a sister, she is “a woman who lives, ministers, and prays within the world. A sister's life is often called ‘active’ or ‘apostolic’ because she is engaged in the works of mercy and other ministries that take the Gospel to others where they are.” A Catholic sister is actively involved in the community with a ministry. She may be involved through various ministries and/or spreading the Gospel to those around her. When looking at SSND, for example, we see sisters out in our communities as teachers, spiritual and retreat directors, volunteers, advocates, chaplains, musicians and more.

Sister Adaire breaks it down further, “An example of women religious who are considered nuns would be the Grey Nuns of the Sacred Heart or the Carmelite communities. Sisters take simple vows and live in a fashion that follows their mission. The School Sisters of Notre Dame, for instance, live in areas where they serve in parish ministries, do social services, work as educators and other ministries. Sisters belong to what are called apostolic communities.

Another notable difference is that while a nun takes solemn vows of poverty, celibacy and obedience, a sister takes the simple vows of poverty, celibacy and obedience. Women religious who profess a solemn vow of poverty renounce ownership of all their earthly goods or possessions. Women religious who profess a simple vow of poverty have a right to retain ownership of their inheritance.

When asked if there was any reference as to a preference in terms - nun versus sister – within the historical documents for the SSND, Michele Levandoski, archivist for the School Sisters of Notre Dame North American Archives, shared, “Since the SSND fall under the category of sister, they have always been sisters. So, there is nothing in the archives that will talk about this difference. People around the sisters might have used the term nun, but the sisters themselves would have used the term sister.” Michele went on to explain, “In my experience working for the Church, I get a sense that people think of women religious as ‘nuns,’ but when addressing a woman religious specifically, they know she is addressed as ‘sister.’

An earlier version of this story was initially published in June 2021.