We introduce a notion of a noncommutative (or quantum) numerable principal bundle in the setting of actions of locally compact Hausdorff groups on C*-algebras. More precisely, we give a definition of a locally trivial G-C*-algebra, which is a noncommutative counterpart of the total space of a locally compact Hausdorff numerable principal G-bundle. To obtain this generalization we have to go beyond the Gelfand-Naimark duality and use the multipliers of the Pedersen ideal. In the case of an action of a compact Hausdorff group on a unital C*-algebra our definition is implied by the finiteness of the local-triviality dimension of the action. Furthermore, we prove that if A is a locally trivial G-C*-algebra, then the G-action on A is free in a certain sense, which in many cases coincides with the known notions of freeness due to Rieffel and Ellwood.