Europium(III) and terbium(III) complexes have been prepared using the ligands 2‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol (HL1) and 2‐(4,5‐dihydro‐1,3‐thiazol‐2‐yl)phenol (HL2) in yields ranging between 74 and 100 %. Metal‐to‐ligand ratios of 1:3 and 1:4 can be achieved, giving rise to compounds with the formulae [Ln2(L)6] and NR4[Ln(L)4], Ln = Eu, Tb. Recrystallisation of the complexes from DMSO resulted in the formation of octanuclear complexes [Na2(Ln(L1)3)2(CO3)(DMSO)2]2 held tightly together by carbonate ions that have been formed from CO2 from the atmosphere. Five structures have been determined, showing a bidentate binding mode of the ligand through the phenolate oxygen and the nitrogen atom of the five‐membered ring. Most terbium compounds show bright luminescence upon excitation with near‐UV radiation, with quantum yields of 16 % to 79 %. Strong emission is observed for NBu4[Eu(L1)4] and NEt4[Eu(L2)4] with quantum yields of 43 % and 20 %, respectively.