The USS Tombaugh was a Federation starship that was in service with Starfleet in the mid-24th century. During the early 2360s, the vessel was under the command of Captain Blackwood.
In 2362, the Tombaugh was attacked and assimilated by the Borg.
An Ensign Stone was a member of the Tombaugh's crew. Stone had studied at Starfleet Academy for four years, and had just completed his, or her, first week of active duty shortly before this assimilation. (VOY: "Infinite Regress")
Franz Joseph's Star Fleet Technical Manual lists a 23rd century starship named USS Tombaugh (NCC-3853), which was listed as a Ptolemy-class (Dollond-subclass) vessel.
The starship may possibly be named for the American astronomer Clyde Tombaugh who discovered the planet Pluto in 1930.