- Legend: The Crawford surname was taken from the barony of Crawford, in 1125, when Norman knights arrived in Scotland with King David I.
- Discounted: Some have claimed that the Crawfords come from Alan Rufus, 1st Earl of Richmond (1040-1093), citing Burke's General Armory and Burke's History of the Commoners as their source. There is no reliable evidence connecting the Crawfords with the Earls of Richmond at this time.
- Theory: Thorlongus, or Thor the Long, known as the Overlord of Crawford, was of Danish and Anglo-Saxon ancestry. He fled to Scotland from his lands in Northumbria, when William the Conqueror invaded England. He was granted lands in the Merse, by King Edgar of Scotland (1097 to 1107). Clan Crawford's connection to Thorlongus has not yet been proven, although current evidence is strong.
- Currently Accepted Origin: Sir Reginald Crawford, 1st sheriff of Ayr, in 1296, produced the main branch of the clan: Crawfords of Auchinames, as well as the secondary branch: Crawfords of Craufurdland. Crawfords of Auchinames received a grant for their lands from Robert the Bruce in 1320.