Theodorus Bailey Myers (December 13, 1821 – June 16, 1888), was an American lawyer, philanthropist, served as a colonel in the U.S. Military, and a collector of books and historical manuscripts.

He also served on the Boards of Managers for the New York Institution for the Blind and the Women's Hospital, where he developed a friendship with fellow collector of Americana, Dr. Thomas Addis Emmet, who would posthumously organize Myers' manuscripts.

[4] At the outbreak of the Civil War, Myers served as quartermaster of the Baltic with the New York 12th Regiment.

During his lifetime, Colonel Myers wrote many brochures on topics of American history.

[7] Among his collection is a complete set of autographs of the signers of the Declaration of Independence, the letters of which he published as a special issue of Historical magazine.