Merton Howard Miller (May 16, 1923 – June 3, 2000) was an American economist, and the co-author of the Modigliani–Miller theorem (1958), which proposed the irrelevance of debt-equity structure.

He shared the Nobel Memorial Prize in Economic Sciences in 1990, along with Harry Markowitz and William F. Sharpe.

He worked during World War II as an economist in the division of tax research of the Treasury Department, and received a Ph.D. in economics from Johns Hopkins University, 1952.

The way in which they arrived at this conclusion made use of the "no arbitrage" argument, i.e. the premise that any state of affairs that will allow traders of any market instrument to create a riskless money machine will almost immediately disappear.

He was survived by his second wife, Katherine Miller, and by three children from his first marriage: Pamela (1952), Margot (1955), and Louise (1958), and two grandsons.