How Many People Are Named William Dennis?
There are approximately 621 people named William Dennis living in the United States today. That makes this name combination uncommon, occurring at a rate of about 1 in 551,939 Americans.
This estimate combines SSA birth records for the first name William with Census Bureau frequency data for the surname Dennis. Below you will find a breakdown of both names, including popularity trends, gender data, and ancestry information.
Estimated People with This Name
621
1 in 551,939 Americans
Combination Rarity
Uncommon
First Name
View full profileWilliam
Last Name
View full profileDennis
William: Popularity Over Time
Year-by-year SSA birth registrations for the first name William. The peak year was 1947 with 67,155 births. The average person named William today is 54 years old.
Ancestry of the Dennis Surname
Self-reported race and ethnicity breakdown for people with the surname Dennis, from the 2010 U.S. Census Bureau.
How we calculated this
The first name "William" has an estimated frequency of 0.681% among living Americans, based on SSA birth records from 1880 to 2024 adjusted for mortality using CDC 2023 life tables.
The surname "Dennis" appears at a rate of 26.61 per 100,000 people in the 2010 U.S. Census.
Multiplying these frequencies against the U.S. population of ~343 million gives 621 estimated people. This assumes first names and last names are statistically independent. Full methodology.
Other people named William
Other people with the surname Dennis
William Dennis: Questions and Answers
How many people are named William Dennis?
We estimate approximately 621 people named William Dennis are alive in the United States today. The first name William is shared by 2,335,115 Americans, and the surname Dennis is shared by 89,381.
How rare is the name William Dennis?
This name combination is classified as Uncommon, occurring at a rate of about 1 in 551,939 Americans. The first name William is very common and the surname Dennis is uncommon.
Is William a male or female name?
William is predominantly male, with 99.6% of bearers being male and 0.4% female. It peaked in popularity in 1947 and the average bearer today is 54 years old.
Where does this data come from?
First name data comes from the Social Security Administration (1880 to 2024), adjusted for survival using CDC 2023 life tables. Surname data comes from the 2010 U.S. Census Bureau. Full methodology.
Try another name
How Many of Me