Long, Lamoreaux & Long was an architectural partnership in Minneapolis, Minnesota, of Franklin B. Long (1842–1912), Lowell A. Lamoreaux (December 23, 1861-February 1, 1922), and Franklin's son Louis L. Long (c.1870-1925).
Franklin B. Long had previously partnered in Long and Kees.
A number of Lamoreaux's, Louis Long's and the firm's works are listed on the National Register of Historic Places.
Works individually by Lamoreaux, by Louis Long, or by the firm include (with attribution):