Thiessen is derived from the German personal name Matthias, which is derived from the apostle Matthaeus (English Matthew). Versions of this name were particularly common throughout Christian Europe throughout the Middle Ages. Today Thiessen is found only in Michigan. Thiessen was first used as a surname by a family from Alsace-Lorraine who settled in Michigan. They were German Protestants and members of the Mennonite church. Most Thiessens were farmers but some became merchants or carpenters. The name has become popular among Christians of German ancestry in the United States. Thiessen was originally written with an s at the end of each word; this is still done in some foreign languages to indicate a plural form of the name. For example, German Matthäusen means "of Matthew", while Mattschen means "of Matt". In English, however, the spelling Thiessen is now preferred because it avoids confusion with the name Matthew. The name Thiessen has been used as a given name by individuals who share the same first name as another person. This has occurred most commonly with boys named Matthew or Michael who have a brother or friend called Thomas. Such pairs of names are often placed in alphabetical order by their respective publishers.