Over the past 110 years, 22 961 girls and 7 443 boys have been named Cleo. The name Cleo ranks 830th in the United States among the most common names for girls. For the first time more than ten times newborns were named Cleo in 1910. The peak of popularity of the name Cleo came in the 1910s and 1920s. You can see absolute numbers and relative numbers on the chart. Indicators per 100K more accurately assess the popularity of the name.