Oh, this is one of my very favorite boy names! *insert girlish “squee” here*
I’m going to have to disagree with NameBerry on this one, though: I don’t think that this name was “everywhere” in the late 1800s/early 1900s. The highest it ever got was #30 (in 1904), when there were only 835 little Theodores born that year. For comparison’s sake, there were 8,108 Johns reported that year. (Now, this is all according to the Social Security website, and there may very probably be some aspect of these numbers that I’m not grasping. But this is what it looks like to me.)
So, why exactly do I like Theodore so much, you may ask? Several reasons. It’s gently old-fashioned, but not in a stodgy way (although this might be a matter of opinion. Several of the comments on Behind the Name are less than favorable in this area). It has a very appealing meaning (“gift of God”).
And the biggest reason of all for my Theodore-love is … the nicknames. Oh, the nicknames! How I love them!
Teddy. An adorable nickname for a little boy. I know a second-grader who goes by this nickname. When I met him in kindergarten, he was roly-poly and good-natured, with chocolate brown hair and big brown eyes. I just about swooned on the spot when I heard his name. But fortunately for him, as he gets older he can choose to go by …
Theo. This is one of the coolest names I can think of. Even cooler than Leo, and without sounding stuck-up. My husband says that this nickname makes him think of the Cosby Show, but I don’t think kids nowadays have ever even heard of the Huxtables. I picture an artistic teenager when I hear the nickname Theo.
Ted. I’m iffy on this one; of all of the Theodore nicknames, this one sounds the stodgiest in my opinion. Ted Bundy — blech. Though there are also many positive associations with Ted, this nickname sounds the most like a Baby Boomer. Stick with the other nicknames, and you’ll be fine.
One possible negative association from the younger set is that dratted Alvin and the Chipmunks movie. But they never use the nicknames for Theodore, to the best of my knowledge, so as long as your son avoids the full form during those few cartoon-crazy years, he should be okay.
Better than okay, because he will have a very versatile and classy name.
from AskOxford
From the French form of the Greek name Theod{o_}ros, derived from theos ‘god’ + d{o_}ron ‘gift’. The name was popular among early Christians and was borne by several saints.
from Behind the Name
From the Greek name Θεοδωρος (Theodoros), which meant “gift of god” from Greek θεος (theos) “god” and δωρον (doron) “gift”. This was the name of several saints, including Theodore of Amasea, a 4th-century Greek soldier; Theodore of Tarsus, a 7th-century archbishop of Canterbury; and Theodore the Studite, a 9th-century Byzantine monk. It was also borne by two popes. This was a common name in classical Greece, and, due to both the saints who carried it and the favourable meaning, it came into general use in the Christian world, being especially popular among Eastern Christians. It was however rare in Britain before the 19th century. Famous bearers include three tsars of Russia (in the Russian form Fyodor), American president Theodore Roosevelt (1858-1919) and American children’s book creator Theodore Seuss Geisel (1904-1991), better known as Dr. Seuss.
from NameBerry
When Theodore Roosevelt took office in 1901, his name was in the Top 40, with Teds and Teddys everywhere. After some damaging stereotypes — the nerdy Chipmunk, Beaver Cleaver’s real name — it went into a decline, from which it is yet to recover.
from Baby Name Wizard
Style: Ladies and Gentlemen
Sisters and Brothers: Beatrice, Eleanor, Alma, Antonia, Josephine, Julius, Frederick, Everett, August, Conrad
A nifty name, bristling with gentlemanly vigor and surprisingly undiscovered in the recent turn-of-the-century revival. Two fine nickname options complete the package: down-to-earth Ted and artistic Theo.
Merry … whatever it is you celebrate! 
