The Saxons (Latin: Saxones, Old English: Seaxe, Old Saxon: Sahson, Low German: Sassen) were a confederation of Germanic tribes on the North German plain, who during the Middle Ages migrated to the British Isles and formed part of the Anglo-Saxons.

The Saxons were originally Ingvaeonic tribes, whose earliest known area of settlement is Northern Albingia, an area approximately that of modern Holstein. This area overlapped the area of the Angles, a tribe with which they were frequently closely linked. Saxons participated in the Germanic settlement of Britain during and after the fifth century. It is unknown how many migrated from the continent to Britain, though estimates for the total number of Anglo-Saxon settlers are around two hundred thousand. During the Middle ages, because of international Hanseatic trading routes and contingent migration during the Middle Ages, Saxons mixed with and had strong influences upon the languages and cultures of the North Germanic and Baltic and Finnic peoples, and also upon the Polabian Slavs and Pomeranian West Slavic people.

The term Anglo-Saxon is used by some historians to designate the Germanic tribes who invaded and settled the south and east of Britain beginning in the early 5th century and the period from their creation of the English nation up to the Norman conquest. The Anglo-Saxon era denotes the period of English history between about 550 and 1066. The term is also used for the language, now known as Old English, that was spoken and written by the Anglo-Saxons and their descendants in England (and part of southeastern Scotland) between at least the mid-5th century and the mid-12th century.

The Benedictine monk Bede, writing in the early 8th century, identified the English as the descendants of three Germanic tribes:

Their language, Old English, which derived from Ingvaeonic West Germanic dialects, transformed into Middle English from the 11th century. Old English was divided into four main dialects: West Saxon, Mercian, Northumbrian and Kentish.

The term Anglo-Saxon can be found in documents produced in the time of Alfred the Great, who seems to have frequently used the titles rex Anglorum Saxonum and rex Angul-Saxonum (king of the English Saxons). The Old English terms ænglisc ('Angle-kin') and Angelcynn ('gens Anglorum') had already lost their original sense of referring to the Angles, as distinct from the Saxons, when they are first attested. In their earliest sense they referred to the nation of Germanic peoples who settled eastern Britain from the 5th century.^{[citation needed]} The indigenous Britons, who wrote in both Latin and Welsh, referred to these invaders as 'Saxones' or 'Saeson' – the word Saeson is the modern Welsh word for 'English people'; the equivalent word in Scottish Gaelic is Sasannach and in the Irish language, Sasanach.