Researchers at the frontier of coordination and organometallic chemistry have synthesized a unique lanthanide–carbon triple bond encapsulated within an endohedral fullerene cage, specifically a cerium–carbide cluster [Ce≡CSc2]@C80. This study deploys X-ray crystallography, spectroscopic methods, and quantum chemical calculations to characterize the Ce≡C bond, revealing an exceptionally short bond length of 1.969(7) Å. The fullerene cage not only stabilizes but also protects the trimetallic carbide cluster, showcasing the unusual bonding affinities between cerium and carbon atoms. This advancement highlights a new dimension in metal–carbon multiple bond chemistry, overcoming previous challenges in isolating lanthanide–carbon double and triple bonds, and opens pathways for further exploration of lanthanide-organic frameworks within protective nanostructures.