Marylou has been given to about 13,112 people in the United States since 1880. It was most common in 1942, which makes it a midcentury name.
Its best year was 1942, when 376 babies were given the name, ranking 361st. The typical living American called Marylou is about 72 years old today.
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.