Honora "Nano" Nagle (c. 1718 – 26 April 1784) was an Irish Catholic religious sister who served as a pioneer of Catholic education in Ireland despite legal prohibitions. She founded the Sisters of the Presentation of the Blessed Virgin Mary, commonly known as the Presentation Sisters, now a worldwide Catholic institute of women religious. She was declared venerable in the Catholic Church on 31 October 2013 by Pope Francis.

Nano Nagle lived during the period when the Catholic majority in Ireland were subject to the anti-Catholic Penal Laws. The Catholic Irish were denied political, economic, social and educational rights that would have lifted them from mass poverty. The parliamentarian and philosopher, Edmund Burke, a younger cousin of Nagle who spent part of his childhood in her birthplace, described those laws: "Their declared object was to reduce the Catholics in Ireland to a miserable populace, without property, without estimation, without education."

Nano Nagle was born in Ballygriffin, in the parish of Killavullen, County Cork, to Garrett and Ann (née Mathew(s) or Matthew(s)) Nagle. Though her exact date of birth is unknown, and the year of her birth disputed, Nagle is most likely to have been born in 1718. The name "Honora" given at baptism was soon replaced in the family circle by the affectionate name "Nano". She was the eldest of six or seven children, the others being Mary (omitted in many sources), Ann, Catherine, Elizabeth, David, and Joseph.

Nagle was born in the Blackwater Valley in County Cork which possesses views of the distant Nagle Mountains. Much of this region was once the property of the Nagle family. Originally known as "de Angulo" or "D'Angulo", they were connected to some of the most prominent local families, and their ancestors had lived in the area for hundreds of years. However, after the Williamite War in Ireland, the Nagle (as they were now known) family's loyalty to the exiled Catholic King James II led to many of their ancestral lands being confiscated by the government. However, when Nagle's parents married, the family still owned considerable property at Ballygriffin, Killavullen. Garret's brother Joseph kept it in nominally Protestant hands so that the family could retain it under the Penal Laws.

Nano Nagle is believed to have attended a local hedge school, like her cousin Edmund Burke, before she travelled to France to complete her education. The Education Act 1695 banned Catholic schoolteachers in Ireland, while also prohibiting overseas travel for Catholic education. Nagle relatives with strong connections in France arranged for Nagle and her sister Ann to travel to Paris, perhaps smuggled in a cargo ship. They finished their schooling and Nagle enjoyed a busy social life in Paris – "balls, parties and theatre outings, all the glamour of the life of a wealthy young lady." After one of these parties, "she noticed a group of wretched-looking people huddled in a church doorway" and was struck by the contrast with her privileged life.

After her father's death in 1746, Nagle and her sister joined their mother in Dublin, witnessing further poverty. Their mother died soon after, and Nagle returned to Paris intending to enter an Ursuline convent, but a religious director advised her to help the poor of her own country instead. She returned to Cork, where her brother Joseph was living, and established her first school for the poor in 1754, "in a rented mud cabin in Cove Lane, in defiance of the law, and in complete secrecy at first, even from her brother." He discovered her secret when a poor man came begging for Nagle to accept his child into her school. "Her brother was very angry with her at first, because of the risks involved, but later became reconciled and gave her his full support."

Nagle's first school opened with about 30 students, and this is now the site of South Presentation convent. At first alone, and later with the support of her family, particularly her uncle Joseph Nagle who had used Protestantism to preserve the family's wealth, she established a network of Catholic schools in Cork. Not everyone in Cork welcomed the initiative: "She was insulted in the street on occasion, and her pupils were dismissed as 'beggars' brats'." Within nine months, she was educating 200 girls. Within a few years, she had opened seven schools, five for girls and two for boys. These provided pupils with a basic education and religious instruction.

She described in a letter her ideas for education, and how she wanted the spiritual and temporal welfare of her pupils to be interwoven and to flow naturally together.