Scottish (Fife and Lanarkshire), northern English, German, and French (mainly Alsace and Lorraine): from an Old English personal name composed of the elements ōs ‘god’ + weald ‘power’. In the Middle English period, this fell together with the less common Old Norse cognate Ásvaldr. The name was introduced to Germany from England, as a result of the fame of Saint Oswald, a 7th-century king of Northumbria, whose deeds were reported by Celtic missionaries to southern Germany. The name was also borne by a 10th-century English saint of Danish parentage, who was important as a monastic reformer. Veneration of Saint Oswald, the king, spread from the German lands to the neighbouring Slavic lands as well. The surname in the (German) spelling Oswald is thus also found especially in Czechia and Slovakia, while in North America it also absorbed various Slavic forms (see 3 below).

Irish (Down): adopted as an English equivalent of Gaelic Ó hEodhusa (see Hussey 1).

Americanized form of Slovenian, Slovak, and Czech Osvald, Slovenian and Slovak Ožvald or Ozvald, and probably also of Slovenian Ožbolt: from vernacular forms of the German personal name Oswald, of Old English origin (see 1 above).