Over the past 110 years, 12 693 girls have been named Gillian. The name Gillian ranks 1142th in the United States among the most common names for girls. For the first time more than ten times newborns were named Gillian in 1945. The peak of popularity of the name Gillian came in the 1990s and 2000s. You can see absolute numbers and relative numbers on the chart. Indicators per 100K more accurately assess the popularity of the name.