The diarylamine scaffold is common in bioactive molecules. Herein, we report a Ru(II)-catalyzed C–N cross-coupling reaction of diazoquinones with arylamines, which provides access to a range of functionalized diarylamines in 43–97% yields. The reaction proceeds under mild and neutral conditions and tolerates various functional groups. The synthetic utility of this method was demonstrated by the modular synthesis of structurally sophisticated diarylamine derivatives and the short synthesis of an anti-inflammatory compound.