The Allis-Chalmers One-Ninety XT, also known as the 190XT, is a row crop tractor produced by Allis Chalmers from 1964 to 1971.

As its model number implies, it was based on the Allis-Chalmers D19 from the D Series, though it featured many alterations and improvements over the D19.

This led to various powertrain failures, especially in earlier models due to a light rear end design.

An improved design was introduced and many tractors were updated with the heavier duty rear end.

Despite stiff market competition from the John Deere 4020 and others, Allis did sell many 190XT tractors, and there are many still working today.