Botolph of Thorney (/ˈbɒtʊlf/; also called Botolph, Botulph or Botulf; later known as Saint Botolph; died c. 680) was an English abbot and saint. He is regarded as the patron saint of boundaries, and by extension, of trade and travel, as well as various aspects of farming. His feast day is celebrated either on 17 June (England) or 25 June (Scotland).

Little is known about the life of Botolph, other than doubtful details in an account written four hundred years after his death by the 11th-century monk Folcard. Botolph was born sometime in the early 7th century to noble Saxon parents who were Christians. He and his brother Adulph were educated by Saint Fursey at Cnobheresburg monastery. They were then sent to study on the Continent, where they became Benedictines. Adulph remained abroad, where he is said to have become a Bishop.

Botolph, returning to England, found favour with a certain "King of the southern Angles", whose sisters he had known in Germany, and was by him permitted to choose a tract of desolate land upon which to build a monastery. The Anglo-Saxon Chronicle records for the year 654: "The Middle Angles, under earldorman Peada, received the true faith. King Anna was killed and Botolph began to build the church at Ikanho".

Botolph founded the monastery of Icanho. Icanho, which means 'ox hill', has been identified as Iken, located by the estuary of the River Alde in Suffolk; a church still remains on top of an isolated hill in the parish. At the time, the site was a tidal island all but surrounded by water, but Botolph attracted other monks and hermits and together they turned areas of marsh and scrub into productive grazing and farm land. The monks built several structures, and the monastery grew. Botolph also worked as an itinerant missionary in East Anglia, Kent and Sussex.

The Life of St Ceolfrith, written around the time of Bede by an unknown author, mentions an abbot named Botolph in East Anglia, "a man of remarkable life and learning, full of the grace of the Holy Spirit". Ceolfrith visited him about the year 670.

Botolph is supposed to have been originally buried at his foundation of Icanho, but in 970 Edgar I of England gave permission for the remains of Botolph to be transferred to Burgh, near Woodbridge, to prevent them from being destroyed by invading Danes. They remained for some fifty years before being transferred to their own tomb at Bury St Edmunds Abbey on the instructions of Cnut. The saint's relics were later transferred again, along with those of his brother Adulph, to Thorney Abbey, although his head was transferred to Ely Abbey and various body parts to other houses, including Westminster Abbey.

Many English churches are dedicated to Botolph. According to the Oxford Dictionary of Saints, 64 ancient English churches were dedicated to him, but later research has suggested the true number may have been as high as 71, with a high concentration of dedications in East Anglia. St Botolph's Church in Boston, Lincolnshire, known locally as "The Stump", is one of the most famous. Boston, or 'Botolph's town' also gave Boston, Massachusetts its name.

St Botolph's Priory in Colchester, Essex, the first Augustinian monastery in England, was built on an earlier Anglo-Saxon church dedicated to Botolph. St Botolph's Church in Hardham, West Sussex, houses some of the most ancient surviving wall paintings in Britain, including the earliest known depiction of St. George in England.