Extemporaneous preaching is a style of preaching that was popular in the late 1800s among Baptist (Primitive Baptist especially), Methodist, Unitarian, and some Presbyterians preachers. Some of the more famous preachers who employed it were Charles Grandison Finney and Peter Cartwright.

The style is not to be confused with impromptu preaching, but involves much preparation. One prepares by dwelling on the subject continually and thus has something to say when the time comes.

The first thing to be observed is, that the student who would acquire facility in this art, should bear it constantly in mind, and have regard to it in all his studies and in his whole mode of study. -Henry Ware, Jr.

On the other hand, it is distinct from memorized preaching. Proponents claim that the importance of preaching demands impromptu preaching.

A reflecting mind will feel as if it were infinitely out of place to present in the pulpit to immortal souls, hanging upon the verge of everlasting death, such specimens of learning and rhetoric. -Charles Finney

Extemporaneous preaching includes both preaching with no written preparation as well as brief notes for the purpose of ordering points.

The disadvantages of such a style is the trade-off of precision for emotional emphasis.