A hybrid zeolite-based catalyst, Ce encapsulated into dealuminated Y zeolite (Ce(salophen)/HY), was synthesized through the ship-in-a-bottle approach and evaluated for the cyclization of ethanolamine with various nitriles to produce oxazoline derivatives. The combination of cerium’s Lewis acidity and the structural confinement of HY zeolite provided high catalytic activity and stability under mild conditions. The optimum results were achieved at Tem:140 °C, 0.15–0.20 mmol catalyst amount, and 30-60 min reaction times. Both aromatic and aliphatic nitriles were effectively converted to the related oxazoline, although electron-withdrawing substituents promoted faster reactions than electron-donating ones. Among them, 4-hydroxybenzonitrile yielded the lowest yield (35%), while 3-chlorobenzonitrile yielded the highest yield (95%). The catalyst was easily recovered, and the catalytic activity was preserved after five successive cycles with negligible cerium leaching. These results indicated that this catalytic system is a robust, recyclable, and environmentally friendly heterogeneous catalyst for the efficient and green synthesis of oxazoline heterocycles.