Marnie has been given to about 6,141 people in the United States since 1880. It was most common in 1969, which makes it a boomer-era name.
Its best year was 1969, when 510 babies were given the name, ranking 428th. The typical living American called Marnie is about 54 years old today. It is relatively most common in Iowa, where it accounts for 0.02% of births.
Source: US Social Security Administration, national and state name files, 2025 release, and the Office for National Statistics for England and Wales. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.