Martin Arthur Armstrong (born November 1, 1949) is the former chairman of Princeton Economics International Ltd. He is known for his economic predictions based on the Economic Confidence Model, which he developed.

In September 1999, Armstrong faced fraud charges by the Securities and Exchange Commission and the Commodity Futures Trading Commission. During the trial, Armstrong was imprisoned for over seven years for civil contempt of court, one of the longest-running cases of civil contempt in American legal history. In August 2006, Armstrong pleaded guilty to one count of conspiracy to commit fraud, and began a five-year sentence.