Sibling names for Theo
Names that sound like they belong in the same family as Theo usually share its era. These sister and brother names rose and fell on a similar curve to Theo, whose busiest decade was the 2020s, and are about as common, so neither child's name will feel dated or unusual next to the other.
Sister names for Theo
| Name | Meaning | Rank 2025 | Babies, last 5 years | Peak decade |
|---|---|---|---|---|
| Magnolia | magnolia (the flowering tree) | #124 | 10,192 | 2020s |
| Oakley | oak clearing (place name) | #156 | 9,099 | 2020s |
| Malani | #374 | 4,175 | 2020s | |
| Palmer | pilgrim | #232 | 5,758 | 2020s |
| Sutton | south farmstead (place name) | #181 | 7,337 | 2020s |
| Salem | #436 | 3,477 | 2020s | |
| Iyla | #525 | 2,377 | 2020s | |
| Sevyn | seven (respelled number word) | #575 | 2,526 | 2020s |
| Aitana | Sierra de Aitana (Spanish place name) | #211 | 6,096 | 2020s |
| Navy | navy (the color or the fleet) | #327 | 4,063 | 2020s |
| Juniper | juniper (the shrub) | #100 | 11,968 | 2020s |
| Poppy | poppy (flower) | #292 | 4,812 | 2020s |
Brother names for Theo
| Name | Meaning | Rank 2025 | Babies, last 5 years | Peak decade |
|---|---|---|---|---|
| Hayes | #162 | 9,631 | 2020s | |
| Wells | springs, wells | #347 | 3,789 | 2020s |
| Arlo | #148 | 11,450 | 2020s | |
| Atlas | #75 | 16,522 | 2020s | |
| Luca | Italian form of Luke | #14 | 39,306 | 2020s |
| Zyaire | #317 | 4,946 | 2020s | |
| Ander | Basque form of Andrew, 'manly' | #728 | 2,312 | 2020s |
| Onyx | onyx (gemstone) | #365 | 4,596 | 2020s |
| Enzo | home ruler (via Heinz, Henry) | #72 | 18,745 | 2020s |
| Banks | at the bank (slope) | #310 | 4,311 | 2020s |
| Brooks | brook, stream (surname) | #64 | 22,965 | 2020s |
Theo's era
Theo ranked #82 for boys in 2025, against #406 in 2015. Its best year was 2023, at #78. A sibling name from the same wave will sound like it was chosen by the same parents; a name from an older or newer wave can make one child's name feel dated next to the other's.
Timeless names that go with any sibling
These names have been used steadily for a hundred years, so they sit comfortably next to a name from any era, Theo included.
Girls: Elizabeth, Maria, Lydia, Cecilia, Julia, Miriam. Boys: Samuel, Anthony, Wesley, Vincent, Calvin, Victor.
Same era, but close to Theo
These names follow Theo's curve too, but we left them out above because they share a first letter or an ending with Theo. Some parents like that echo; if you do, start here.
- Thiago same first letter as Theo
How these were chosen
Each suggestion's share of US babies has followed a curve close to Theo's since 1880, and its recent number of babies is within about twelve times Theo's, so the names are in the same league. Names starting with the same letter as Theo or with the same ending are left out, so the names go together without matching. Spellings of Theo itself are excluded.