16 in D major, K. 451, is a concertante work for piano, or pianoforte, and orchestra by Wolfgang Amadeus Mozart.

Mozart composed the concerto for performance at a series of concerts at the Vienna venues of the Trattnerhof and the Burgtheater in the first quarter of 1784, where he was himself the soloist.

[2] The work is orchestrated for solo piano, flute, two oboes, two bassoons, two horns, two trumpets, timpani and strings.

The concerto is in three movements: Simon Keefe has noted contemporary comments from Mozart's era on how the woodwind writing in this concerto showed a "newly intricate and sophisticated" character compared to Mozart's prior keyboard concerti.

[1] M. S. Cole has noted Mozart's use of meter changes in the coda of the finale, starting at measure 315, from 24 to 38, and subsequent thematic transformations.