Hilmer is of Germanic origin, derived from the word 'helm', which means 'helmet'. It is considered an alternate form of Heinrich, and was brought to England by early Anglo-Saxon settlers. In medieval times, Hilmer was used in Germany as a personal name, but it has since become quite rare. Today, Hilmer is more commonly found in Scandinavian countries, where it is often used as a middle name.
The name Hilmer experienced significant fluctuations in popularity over the years, with a notable peak during World War I and early post-war era. Between 1912 and 1923, there were consistently high numbers of births with the name Hilmer, reaching as many as 28 in some years. However, by the mid-1920s, this popularity started to decline, with fewer than 25 births per year after 1925. After the 1940s, the name seemed to have fallen out of favor, with only one instance of a Hilmer birth in 2005, indicating a total of 499 births over the recorded period.