The formation of endohedral metallofullerenes (EMFs) in an electric arc is reported for the mixed‐metal Sc–Ti system utilizing methane as a reactive gas. Comparison of these results with those from the Sc/CH 4 and Ti/CH 4 systems as well as syntheses without methane revealed a strong mutual influence of all key components on the product distribution. Whereas a methane atmosphere alone suppresses the formation of empty cage fullerenes, the Ti/CH 4 system forms mainly empty cage fullerenes. In contrast, the main fullerene products in the Sc/CH 4 system are Sc 4C 2@C 80 (the most abundant EMF from this synthesis), Sc 3C 2@C 80, isomers of Sc 2C 2@C 82, and the family Sc 2C 2 n (2 n=74, 76, 82, 86, 90, etc.), as well as Sc 3CH@C 80. The Sc–Ti/CH 4 system produces the mixed‐metal Sc 2TiC@C 2 n (2 n=68, 78, 80) and Sc 2TiC 2@C 2 n (2 n=80) clusterfullerene families. The molecular structures of the new, transition‐metal‐containing endohedral fullerenes, Sc 2TiC@ I h ‐C 80, Sc 2TiC@ D 5 h ‐C 80, and Sc 2TiC 2@ I h ‐C 80, were characterized by NMR spectroscopy. The structure of Sc 2TiC@ I h ‐C 80 was also determined by single‐crystal X‐ray diffraction, which demonstrated the presence of a short Ti=C double bond. Both Sc 2TiC‐ and Sc 2TiC 2‐containing clusterfullerenes have Ti‐localized LUMOs. Encapsulation of the redox‐active Ti ion inside the fullerene cage enables analysis of the cluster–cage strain in the endohedral fullerenes through electrochemical measurements.