Macintosh, the range of Apple computers more commonly referred to as "Macs", take its name from a Scottish clan.
Apple employee Jef Raskin chose to name the range after his favourite apple - the McIntosh. The spelling was later changed to MacIntosh because the McIntosh name was already trademarked by a New York audio equipment manufacturer.
The apple itself takes it name from a farmer called John McIntosh, the son of Scottish migrants, who discovered and developed a variety of apples known as the McIntosh Red in Upper Canada in the early 1800s.
Sources: Insanely Great: The Life and Times of Macintosh, the Computer That Changed Everything| Great Scottish Clans