Celtic knots are a variety of knots and stylized graphical representations of knots used for decoration, used extensively in the Celtic style of Insular art. These knots are most known for their adaptation for use in the ornamentation of Christian monuments and manuscripts, such as the 8th-century St. Teilo Gospels, the Book of Kells and the Lindisfarne Gospels. Most are endless knots, and many are varieties of basket weave knots.

The Book of Kells is an illuminated manuscript and Celtic Gospel book in Latin, containing the four Gospels of the New Testament together with various prefatory texts and tables. It was created in a Columban monastery in either Ireland or Scotland, and may have had contributions from various Columban institutions from each of these areas. It is believed to have been created c. 800 AD. The text of the Gospels is largely drawn from the Vulgate, although it also includes several passages drawn from the earlier versions of the Bible known as the Vetus Latina. It is regarded as a masterwork of Western calligraphy and the pinnacle of Insular illumination. The manuscript takes its name from the Abbey of Kells, County Meath, which was its home for centuries.