Keith Thomas Armstrong (born 11 October 1957) is a former footballer who played in the Football League for Sunderland, Newport County and Scunthorpe United, and in Finland for a number of clubs, where he also coached.
Born in England, Armstrong became a naturalised Finn in the early 1990s, and enjoyed a long and successful coaching career in Finland with Rovaniemen Palloseura, TP-Seinäjoki, FC Haka and most recently HJK Helsinki.
Armstrong is one of the most successful football managers in the Finnish league, having won five Veikkausliiga championships, two Finnish Cups, and two Manager of the Year awards.