thumb|350px|Mixed-interval chords from the opening to [[Arnold Schoenberg's Klavierstück Op. 33a ().]]
In music a mixed-interval chord is a chord not characterized by one consistent interval. Chords characterized by one consistent interval, or primarily but with alterations, are equal-interval chords. Mixed interval chords "lend themselves particularly" to atonal music since they tend to be dissonant.
thumb|350px|right|[[Interval cycles: C1–C4 and C6; feature equal-intervals.]]
Equal-interval chords are often of indeterminate root and mixed-interval chords are also often best characterized by their interval content.