Asa William Henry Clapp (March 6, 1805 – March 22, 1891) was a United States representative from Maine.
Clapp, son of wealthy merchant and state legislator Asa Clapp (1762–1848), was born in Portland, Maine, in 1805.
He engaged as a merchant in foreign and domestic commerce in Portland.
He was a delegate to the 1848 and in 1848 and 1852 Democratic National Conventions.
He then resumed his former business pursuits, also serving as a director of the Maine General Hospital and of the Portland Public Library until his death in Portland in 1891.