I have known for a long time that several people who went on to become well known in the entertainment and film industry were born in or otherwise had connections to Joplin. Ones that come immediately to mind include Dennis Weaver (Chester on Gunsmoke
), Robert "Bob" Cummings (who starred in movies and had his own TV show during the 1950s), and Percy Weinrich, a ragtime composer in the early 1900s known for such songs as "Put on Your Old Gray Bonnet"), and John Beal, a serious actor who played opposite famous actresses like Helen Hayes and Katharine Hepburn during the 1930s.
One famous actress from Joplin that I, however, was not aware of until very recently was Pauline Starke (photo below). She was born in Joplin in 1901 and went on to star in silent films during the late 1910s when she was just a teenager. Her fame continued into the early and mid-1920s but began to peter out in the late 1920s. She lived until 1977, however, dying in Santa Monica, California, at the age of 76.
There might be one or two other lesser known people from Joplin who succeeded in show business or the entertainment business, but these, I think, are the main ones. Certainly there were other famous people, such as the poet Langston Hughes, but I don't really consider writing poetry show business, even though Hughes did, I think, sometimes give public readings of his poems.