Over the past 110 years, 5 girls and 111 241 boys have been named Josiah. The name Josiah ranks 20189th in the United States among the most common names for girls. For the first time more than ten times newborns were named Josiah in 2004. The peak of popularity of the name Josiah came in the 2000s. You can see absolute numbers and relative numbers on the chart. Indicators per 100K more accurately assess the popularity of the name.