How Many People Are Named Castor?
people named Castor are alive in the United States today (estimate)
About 1 in 885,452 people in the US has this name
Based on 390 babies named Castor in Social Security records from 1998 to 2025, and the share of each birth year still alive in 2025.
Popularity Rank
💎💎 Very Rare
Peak Year
29 births
Trend
Stable (last 10 years)
📖 Name Origin & Meaning
Meaning:
From the Greek name Καστωρ (Kastor), possibly related to κεκασμαι (kekasmai) meaning "to excel, to shine" (pluperfect κεκαστο). In Greek myth Castor was a son of Zeus and the twin brother of Pollux. The constellation Gemini, which represents the two brothers, contains a star by this name.
Source of the meaning, origin, pronunciation and related names: Behind the Name.
Related & Similar Names
⚧ Gender Distribution
All of the babies given the name Castor in the records were boys.
👥 Age Distribution
The average person named Castor alive today is about 11 years old, and 100% are under 30. Half of them were between 5 and 16 in 2025.
📈 Popularity Over Time
Castor first appears in the records in 1998 and was given most often in 2016, to 29 babies. In 2025, 21 babies got the name.
Babies given the name each year, 1998 to 2025
🏆 Rank History
Castor has never been one of the 100 most popular boys' names. Its best rank was #3,701, in 2016. In 2025 it ranked #4,733.
| Boys | |
|---|---|
| Rank in 2025 | #4,733 |
| Best rank | #3,701 (2016) |
| Years in the top 100 | None |
| Rank in its biggest decade | #5,259 in the 2010s |
📍 State-Wise Distribution
People named Castor alive today, by the state where they were born (estimate; state records start in 1910).
More people named Castor were born in California than in any other state: about 5 of those alive today.
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