An algebra A is homogeneous if
its automorphism group acts transitively on the set of one dimensional subspaces of
A. In this paper the structure of all three dimensional homogeneous algebra is
determined. These fall into three classes: (1) truncated quaternion algebras over
formally real Pythagorean fields; (2) an algebra over GF(2) in whlch x2= x for all
x in A, and (3) two algebras over GF(2) which are generated by each of
their nonzero elements. The automorphism group is determined in each
case.