Daily AncestorTheo.
Theo. is an old abbreviation of the first name Theodore, found in deeds, wills, church registers and census pages.
Theo. is a clerk's shortening of the given name Theodore. Busy writers cut common first names down to a few letters, often raising the last letters above the line, and the habit runs through deeds, wills, tax lists and census pages.
Several names begin with these letters, so do not assume the man was Theodore without a fuller spelling elsewhere. Theo. is a starting point for your search, not the final answer.
As seen in a recordName column of the 1880 census
Theo. Gray, 22, Clerk, Mass.
Sources
How to cite this page
Daily Ancestor. "Theo.." Dictionary of Old Record Words. https://dailyancestor.com/dictionary/abbreviations/theo. Last checked 2026-10-01.