Merwyn has been given to about 796 people in the United States since 1880. It was most common in 1937, which makes it a interwar name.
Its best year was 1937, when 38 babies were given the name, ranking 1050th. The typical living American called Merwyn is about 87 years old today.
Source: US Social Security Administration, national and state name files, 2025 release. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.