Dual-reflector antennas have been investigated for omnidirectional coverage, where the reflector surfaces are bodies of revolution obtained by spinning confocal conic sections or shaped generating curves about a common symmetry axis [1]–[3]. Closeform design equations have been derived for omnidirectional arrangements generated by axis displaced conic sections [4]–[6]. The geometrical optics (GO) aperture field was also derived but only for broadside-pattern geometries [4]. The aim of this work is to complement the previous investigations by deriving the GO aperture field of omnidirectional axis-displaced dual-reflector antennas with an arbitrary main-beam direction in the elevation plane. GO principles [7] are employed to obtain the vector field at the antenna conical aperture. The radiation pattern is then obtained by the aperture field method (ApM). Case studies are analyzed by the accurate momentmethod (MoM) technique to validate the GO-ApM analysis procedure.