The anelastic and magnetic relaxation behavior of face‐centered cubic NiCoC alloys has been investigated. In addition to magneto‐mechanical background damping, three relaxation processes have been observed: (1) an interstitial reorientation relaxation of carbon‐containing point defects; (2) a long range migrational relaxation of carbon defects to Bloch walls; and (3) a Zener reorientation relaxation of substitutional atoms. The carbon reorientation relaxation is predominantly a relaxation of single carbon atoms in sites made asymmetric by the presence of the substitutional alloying element. The carbon migrational relaxation is manifested as a reversible decay of the magneto‐elastic component of the anelastic reorientation peak during aging and as an apparent Dietze‐type phenomenon in the magnetic relaxation spectrum.