Orphaned as a small child Lopez took his adoptive parents’ name. He became a popular vaudeville and circus act, singing, dancing, playing several instruments and juggling, and was also an accomplished acrobat. On Broadway, in 1923 and again the following year he appeared in Earl Carroll Vanities. He continued his vaudeville career but was later in Rain Or Shine (1928), which had book by James Gleason and Maurice Marks, music by Milton Ager and Owen Murphy, lyrics by Jack Yellen. Staged at the George M. Cohan Theatre, the show ran for 356 performances. In the role of Smiley Johnson, Cook had a feature with ‘So Would I’. He reprised the role in the 1930 film version of the show. He took the starring role of Joe Squibb in Fine And Dandy (1930), singing ‘Giddyup Back’ and the show’s title song, composed by Kay Swift and Paul James and performed as a duet with Alice Boulden who was Cook’s second wife. Cook made an uncredited contribution to the book, which was otherwise by David Ogden Stewart. The show ran at Erlanger’s Theatre for 255 performances.

Cook produced and starred in Hold Your Horses (1933), with music and lyrics by Robert Russell Bennett, Robert A. Simon, Louis Alter, Arthur Swanstrom, Ben Oakland and Owen Murphy, and book by Russell Crouse and Corey Ford. The show ran for only 88 performances at the Winter Garden Theatre. In addition to his role as Broadway Joe, Cook also regaled the audience with many of his vaudeville routines. Billed as Joe Cook Jnr., he was in Broadway Sho-Window (1936), which closed after 12 days, despite being produced and staged by the usually sure hand of Gus Edwards, who also wrote the music with lyrics by Eugene Conrad. Cook was in the play, Off To Buffalo (1939), which closed after only seven performances.

In the 40s, Cook appeared in It Happens On Ice (1940), presented by Sonart Productions, Inc., a company co-owned by Sonja Henie, that ran at the Center Theatre for 276 performances. Music for this show was by Vernon Duke, Fred E. Ahlert and Peter De Rose, lyrics by Al Stillman. Cook’s few film appearances included Give ’Im Air, as himself, The White Hope and Arizona Mahoney (all 1936), playing the title role in the latter.