Tedford seems to be an English surname from a place name. I can't find a direct reference to it in my reference books, but other English place names which have
Ted as a first syllable (Tedstone, Tedburn, and Teddington) all seem to go back to an Old English given name, Tette, Teotta, or Teod. It is uncertain what this originally meant, but some experts guess that it could be a variation of the syllable
theod- which occurs in old Germanic names and meant "people."
The above information is from a combination of Hanks & Hodges'
A Dictionary of Surnames and A. D. Mills'
A Dictionary of English Place-Names.