Dennis H. Klatt (March 31, 1938 – December 30, 1988) was an American researcher in speech and hearing science.

Prior to his work, non-verbal individuals would need specialist support to be able to speak at all.

He joined the Massachusetts Institute of Technology as an assistant professor in 1965, becoming a senior research scientist in 1978, and remained a member of the MIT faculty until his death.

An author of more than 60 scientific papers, Klatt was awarded the Silver Medal in Speech Communication by the Acoustical Society of America for "fundamental and applied contributions to the synthesis and recognition of speech",[3] and the John Price Wetherill Medal by the Franklin Institute "for the design of a machine that can articulate written language", both in 1987.

He died in Cambridge, Massachusetts, on December 30, 1988, after a long struggle with cancer which also took his voice.