Sidnei
Meaning
the Brazilian spelling of Sidney, an English surname underneath; a 1960s and 70s Brazilian standard
Popularity, 1890–2024
Sidnei does not appear in US Social Security baby-name records, which list only names given to at least five babies in a year. There is no popularity curve to chart: a genuinely rare pick.
Popularity in Brazil
64,272 people · the #476 first name in Brazil · about 1 in 3,165 · median age 44
Among people named Sidnei living in Brazil at the 2022 census, more were born in the 1970s than in any other decade.
The census also counted 119 born between 2020 and August 2022, too recent a span to chart.
Source: IBGE, Censo Demográfico 2022
See Sidnei in official records · Spain
Spain
34 residents · #20,047 among men · mean age 45.9
Residents of Spain on 1 January 2025. Spain publishes how old a name’s living bearers are, not a birth series, so there is no year chart.
Source: INE (Spain), Censo de Población anual, 1 January 2025
Not on the record in Mexico City, Argentina and Puerto Rico: those registries withhold small counts, so rare uses may sit below their floors.
Keep exploring
The Sidnei deep dive
Whether you’re naming a baby or exploring your own name’s history, this is a personal letter, not a list: where Sidnei 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 Sidnei fits with your family’s names and surname.
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