Dennis
The story
Dennis is the usual English, German and Dutch form of Denis, says Behind the Name, and Denis is the medieval French form of Dionysius; Saint Denis, the third-century missionary and first bishop of Paris, was martyred by decapitation, after which legend says he picked up his own severed head and walked. The American ledger wrote a vast midcentury arc under this name: about 920 boys in the 1890s, about 26,400 in the 1930s, about 162,100 in the 1940s and about 204,300 in the 1950s, then the long descent, about 95,000 in the 1960s down to about 2,410 so far this decade. Brazil counts about 4,300, median age thirty. A god's name filtered through a headless saint, and a ledger that needed six digits twice.
Dennis's name family
One shared root links 4 names across 2 languages.
Shared root: from Greek Dionysios "devoted to Dionysus", carried west as Saint Denis of Paris
The constellation
More branches
Popularity, 1890–2024
Shape drawn from US Social Security baby-name records. Dennis peaked in the 1950s.
See popularity in Brazil
Popularity in Brazil
4,322 people · the #3,038 first name in Brazil · about 1 in 47,619 · median age 30
Among people named Dennis living in Brazil at the 2022 census, more were born in the 1990s than in any other decade.
The census also counted 107 born between 2020 and August 2022, too recent a span to chart.
Source: IBGE, Censo Demográfico 2022
When you meet Dennis
People given the name Dennis in the United States span the generations: the middle half were born anywhere from 1950 to 1979. Age is the one thing the name won't tell you.
Estimated from US Social Security birth registrations and typical lifespans; a rough guide, not a rule.
The Dennis deep dive
Whether you’re naming a baby or exploring your own name’s history, this is a personal letter, not a list: where Dennis truly comes from, how it traveled, and what a century of records reveals. If you have grown a tree on nametree, it also considers how Dennis fits with your family’s names and surname.
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