Bishop of Kilroot and a contemporary of St. Ailbe
Saints
Here is CatholicBrain's index of Saints. This is a great resource for learning about the lives of the saints at home or in the classroom!

Saint Macrina the Younger
Granddaughter of St. Macrina the Elder, and the sister of St. Gregory of Nyssa. She died in 379
Saint Malachy
Abbot of Bangor, later Archbishop of Armagh, d. 1148. Article includes testimony from St. Bernard of Clairvaux on St. Malachy's character

Saint Margaret
Also known in the Christian East as St. Marina. Virgin and martyr from Pisidian Antioch

Saint Margaret Clitherow
Martyr, d. 1586, who is called the 'Pearl of York.' St. Margaret was crushed to death for the crime of harboring priests

Saint Margaret Mary Alacoque
Apostle of the devotion to the Sacred Heart of Jesus

Saint Margaret of Cortona
Third Order Franciscan, d. 1297

Saint Margaret of Scotland
Eleventh-century queen
Saint Margaret Ward
English martyr, died at Tyburn in 1588

Saint Maria Goretti
Born on October 16 1890 in Corinaldo, in the Ancona Province in Italy, her farmworker father moved his family to Ferrier di Conca, near Anzio. When he died of malaria, Maria's mother had to struggle to feed her children
Saint Maris, Martha, Audifax, and Abachum
Family martyred at Rome in 270. SS. Maris and Martha were husband and wife.

Saint Martha
Sister of Mary of Bethany and of Lazarus
Saint Mary Magdalen de' Pazzi
17th-century Carmelite mystic

Saint Mary of Egypt
Penitent and hermit, who died around 421

Saint Matilda
Queen of Germany, wife of Henry I (the Fowler). She died in 968

Saint Matthew
The Apostle and Evangelist, in Scripture and tradition

Saint Matthias
The Apostle, in Scripture and legend

Saint Maurice
Leader of the Theban Legion, killed around 287

Saint Maximus of Turin
Bishop and theological writer, b. probably in Rhaetia, about 380; d. shortly after 465
Saint Melito
Bishop of Sardis, ecclesiastical writer, latter half of the second century

Saint Michael the Archangel
Saint Michael the Archangel isn't a saint, but rather he is an angel, and the leader of all angels and of the army of God.

Saint Monica
Widow, d. 387. The mother of St. Augustine of Hippo

Saint Mother Teresa
St.Teresa of Calcutta The remarkable woman who would be known as Mother Theresa began life named Agnes Gonxha Bojaxhiu. Born on August 26, 1910 in Skopje, she was the youngest child born to Nikola and Drane Bojaxhiu, Receiving her First Communion at the age of five, she was confirmed in November 1916. Her father died while she was only eight years old leaving her family in financial straits.