In a process for producing a methyl-substituted biphenyl compound, at least one methyl-substituted cyclohexylbenzene compound of the formula: wherein each of m and n is independently an integer from 1 to 3, is contacted with a dehydrogenation catalyst under conditions effective to produce a dehydrogenation reaction product comprising at least one methyl-substituted biphenyl compound. The dehydrogenation catalyst comprises an element or compound thereof from Group 10 of the Periodic Table of Elements deposited on a refractory support, such as alumina.