Sinclaire has been given to about 229 people in the United States since 1880. It was most common in 1995, which makes it a Gen X and millennial name.
Its best year was 1995, when 20 babies were given the name, ranking 5000th. The typical living American called Sinclaire is about 21 years old today.
Source: US Social Security Administration, national and state name files, 2025 release. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.