It is known that the
maximal order of a cyclic group of automorphisms admitted by a Klein surface or
real algebraic curve of algebraic genus p is 2p or 2(p + 1), depending on whether p is
odd or even. In this paper, we classify the automorphism groups of all non-orientable
Klein surfaces, without boundary, which admit an automorphism group of order 2p,
or 2(p + 1). We determine that the automorphism groups are cyclic precisely when
the surfaces are hyperelliptic. Defining equations for all but one family of these Klein
surfaces are given.