Old Saxon, also known as Old Low German, is the earliest recorded form of Low German, documented from the 8th century until the 12th century, when it evolved into Middle Low German. It was spoken on the north-west coast of Germany and in the Netherlands by Saxon peoples. It is close enough to Old Anglo-Frisian (Old Frisian, Old English) that it partially participates in the Ingvaeonic nasal spirant law; it is also closely related to Old Low Franconian ("Old Dutch"). It was mutually intelligible with Old English.

Old Saxon does not participate in the High German consonant shift, and thus preserves stop consonants p, t, k that have been shifted in Old High German to various fricatives and affricates. The Germanic diphthongs ai, au consistently develop into long vowels ē, ō, whereas in Old High German they appear either as ei, ou or ē, ō depending on the following consonant. Old Saxon, alone of the West Germanic languages, consistently preserves Germanic -j- after a consonant, e.g. hēliand "savior" (Old High German: heilant, Old English: hǣlend, Gothic: háiljands). Germanic umlaut, when it occurs with short a, is inconsistent, e.g. hebbean or habbian "to have" (Old English: hebban). This feature was carried over into the descendant-language of Old Saxon, Middle Low German, where e.g. the adjective krank (sick/ill) had the comparative forms krenker and kranker. Apart from the E, however, the Umlaut is not marked in scripture.

Old or OLD may refer to:

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.