Three new hybrid bis(salicylaldiminato)/calix[4]arene ligands H 4L1-H 4L3 have been synthesized and investigated with regard to their coordination behavior toward the UO 2 2+ cation. The ligands H 4L1 and H 4L2, derived from bis-1,3-amino-ethoxy-functionalized calix[4]arenes and 3-methoxy-2-hydroxy-salicylaldehydes, react readily with uranyl nitrate in the presence of NEt 3 to support mononuclear neutral complexes with a 1:1 metal:ligand stoichiometry, namely [UO 2(H 2L1)] ( 6) and [UO 2(H 2L2)] ( 7). Ligand H 4L3, with an additional alanyl linker connecting the bis(2-amino-ethoxy)-calix[4]arene backbone and the 3-methoxy-2-hydroxy-salicylaldehyde arms, supports a neutral, mixed-ligand dinuclear uranyl complex [(UO 2) 2(MeO) 2(H 2L3)] ( 8). The ligands H 4L1 and H 4L2 act as pentadentate O 4N ligands for the UO 2 2+ ion to produce a distorted pentagonal bipyramidal coordination environment (O 6N donor set). The ligand H 4L3 supports a binuclear [UO 2(μ-OMe) 2UO 2] 2+ core unit, whose terminal coordination sites are occupied by the donors of the two pendant arms of H 4L3. The spectroscopic properties (NMR, IR, UV-Vis, ESI-MS) suggest that the complexes 6 and 7 retain their integrity in solution state. The structures are further stabilized by intramolecular hydrogen bonding interactions, as implied by computational analyses (NCI plots). These findings provide valuable insight into the influence of spatial flexibility and donor arrangement on the uranyl coordination chemistry of calix[4]arene-based ligand systems.