Let (M-3,g) be a three dimensional almost coKahler manifold such that the Reeb vector field xi is an eigenvector field of the Ricci operatorQ, i.e.Q xi=rho xi, where rho is a smooth function onM. In this article, we prove that ifgrepresents a Cotton soliton with potential vector field being collinear with xi, or a gradient Cotton soliton, thenMis coKahler or locally conformally flat. Furthermore, whengrepresents a nontrivial Cotton soliton with potential vector field being orthogonal to xi, we prove thatMis coKahler or locally isometric to one of the following Lie groups:E(2) orE(1,1) if rho is constant along xi. Finally, for a (kappa,mu,nu)-almost coKahler manifold, we also consider thatgis a nontrivial Cotton soliton with potential vector field being orthogonal to xi.