Classic and elegant but with boyish charm, Theodore has become hit name in recent years, vaulting into the US Top 10 in 2021 for the first time ever and into the Top 5 in 2024. A favorite in English speaking countries, it also ranks highly across the UK and Ireland, and in Canada, New Zealand, and Australia.

Tessa is one of those golden names that's been popular but not TOO popular for several decades now. Tessa has ranked in the Top 500 in the US since 1981 but has risen only once above Number 200.

Thea is a diminutive of names ending in -thea, including Dorothea, Althea, and Anthea. It is also the Anglicized spelling of Theia, the Titan of sight, goddess of light, and mother of the moon. She was the consort of Hyperion, and mother of Helios, Selene, and Eos.

See the popularity graph below for the name Theo? It's been heading straight uphill since 2010, when it hopped back onto the Top 1000 after a 60+ year absence.

Tobias is one of a number of s-ending boys' names that are riding a wave of popularity. With its Old Testament-Dickensian feel, it's a name with a distinguished pedigree.

Thalia was one of the Three Graces in Greek mythology, and also the Muse of comedy and pastoral poetry, making this a Hellenic choice worthy of consideration.

The popular appeal of the strong, intelligent Saint Teresa of Avila, combined with the selfless compassion of the more recent Mother Teresa, have fused to give this second-tier classic a somewhat noble, religious image. Although the origins of the name are uncertain, it has been prevalent particularly in forms Theresa, Teresa, and Therese throughout Europe for centuries.

A second-tier classic, the New Testament Timothy moves in and out of fashion more than John and James. But though it peaked in the 1960s, many modern parents still appreciate its familiarity and lively rhythm. And the short form Tim feels eternally boyish.

Tina, despite its petite and tinkly image, is apt these days to be replaced by the more elegant originals, Christina and Martina.It does have some strong namesakes, though, in Tina Turner (born Anna Mae), Tina Brown (born Christina), Tina Fey (born Elizabeth), and photographer Tina Barney (born Tina).

Toula came to light as the name of the heroine of "My Big Fat Greek Wedding," short for Fotoula, a variant of Fortini, a feminine version of Fotis or Fotios, meaning "light".

Tansy is a flower name rarer than Rose, livelier than Lily and a lot less teasable than Pansy.

A paramour of Alexander the Great and the heroine of a Jules Massenet opera based on the life of a fourth century Egyptian saint, this name is nothing if not dramatic. Often spelled with a diaeresis or umlaut -- aka two dots -- over the letter i, Thais is a Top 100 girls' name in France and is also popular in Spain. 

One of the first luxury brand names and the quintessential Booming Eighties status-conscious moniker; used by Donald Trump for his daughter, Tiffany has plummeted far from its high in the Top 25.

Theon, an ancient name attached to a noted Greek teacher of mathematics and astronomy, also father to the first woman mathematician, might appeal to parents in this field. You can think of Theon as Theo with something a little extra.

Theia is the Titan of sight and the shining light of the clear blue sky. She is the consort of Hyperion, and mother of Helios, Selene, and Eos. The name is more familiar in its Anglicized version, Thea.

Thisbe, the name of a beautiful but tragic lover in mythology, is lively and cute -- in a slightly thistly, prickly way. Ovid retold the story of Thisbe and Pyramus, young lovers in ancient Babylon kept apart by family rivalry, which was the inspiration for Romeo and Juliet. A modern bearer of the name is writer Thisbe Nissen.

In Sarah Dessen's novel Along for the Ride, the baby daughter is named Thisby, nn Isby.

Theo has a girls' name is used for only a handful of babies today. As a short form of Theodora, Theo is used much less frequently than Thea or even Teddy. One notable appearance was as the younger daughter in Sofia Coppola's film On the Rocks in 2020.

This feminine form of Theodosius has long been buried deep in the attic, but might be a good discovery for the parent who wants to move beyond Theodora. Vice President Aaron Burr named a daughter Theodosia ("Dear Theodosia" is a song in the smash musical Hamilton), and it was the birth name of silent screen vamp Theda Bara. Theodosia actually appeared on the US popularity lists in the 1880s and 90s.

A name with a number of variations including the Danish Tyge, the Swedish Tyko, and the Dutch Tygo, which are popular throughout modern Europe. Tycho was also the name of both a 5th century Greek saint and the Danish astronomer, Tycho Brahe.

Tim is a boyish short form occasionally given on its own. There were 37 baby boys named Tim in the US last year, versus over 1700 named Timothy.