Conformal manifolds \(M_\lambda \) are open subsets of \(\mathbb {R}^n\) endowed with the metric \(\begin{aligned} g_\lambda =\frac{dx_1^2+\ldots +dx_n^2}{\lambda ^2} \end{aligned}\) where \(\lambda \) is called the conformal function. We show that there exists the \(\alpha \) -Dirac operator \(D_\alpha \) , with \(\alpha \in \mathbb {R}\) , acting on functions valued by the Clifford algebra on \(M_\lambda \) . The operator behaves similarly to the usual Euclidean Dirac operator. We develop \(\alpha \) -dependent potential theory for \(\Delta _\alpha \) on conformal manifolds, prove refined Poincaré lemmata, and establish Helmholtz-type decompositions for multivector fields.