English: Gary Cooper's star in the sidewalk outside the Ellen Theater (17 West Main), in Bozeman, Montana. Cooper was a famous movie star from Helena, Montana, who acted from the 1930s to the 1960s.

The Ellen was not the city's first movie theater. The Bozeman Opera House had been showing kinetoscopes and motion pictures occasionally since 1900 or so. The Lyric Theatre (vaudeville and movies) was built in June 1908, the Orpheum (vaudeville and movies) in late 1908, and the Gem Theater (vaudeville and movies) in 1919.

In 1916, Gallatin Amusements was formed to build a new movie and vaudeville theater in Bozeman. The initial price was $75,000. The theater was the brainchild of T. Byron Story and Nelson Story, Jr., sons of city founding father Nelson C. Story, Sr.; H.R. Greene; E.H. Kleinschmidt; and Otto Schmidt. The Storys were the majority investors, and the theater was named "The Ellen" after their mother, Ellen Trent Story.

The theater cost a whopping $150,000 to build. The 850-to-900 seat theater (it depended on the configuration) had an Italianate interior design style, courtesy of the ever-present local architect Fred Willson. The theater featured a hardwood stage with wings, half-fly grid system, apron, spacious and numerous dressing rooms, and proscenium that could host both live performances and screen motion pictures. (It is a myth that the Ellen was the first theater in Bozeman designed exclusively for motion pictures.) Floor and balcony seating were available, and the balcony featured loge seating (a box at the front of the balcony). Loge and floor seats were permanently reserved for members of the Story family. The second floor of the Ellen Theater had a dance hall and dining room with hardwood floors specially deadened so that sound could not be communicated to the theater below. A confectionary shop was purposed-built next to the theater box office.

The Ellen Theater opened on December 1, 1919. George Loane Tucker's movie "The Miracle Man" was screened, followed by a vaudeville show. A local man, “Popcorn Johnny”, became a Bozeman legend for dispensing popcorn from a wagon in front of the Ellen Theater.

In January 1925, a $16,000 Wurlitzer organ (with the registry number "Opus #979") was installed in the theater. The Wurlitzer is a Style EX (two chambers) with two manuals. It remains in working order and is still used as of 2013. The Ellen was remodeled in 1931 to improve its accoustics so that it could accommodate sound motion pictures. The interior was also refurbished. Shortly thereafter, the Russell family purchased a controlling interest in the Ellen Theater from the Story family. (They also purchased the Rialto Theater, directly across the street.)

By the mid-1970s, the Ellen Theater was in disrepair. Live theater was no longer a draw for audiences, and competition from new movie theaters, drive-in theaters, and television kept audiences away. No remodeling or refurbishment had occurred in more nedarly four decades. The theater struggled throughout the 1980s, closing for short periods of time. Carmike Cinemas ran the Ellen as a movie house by the 1990s. In 2001, Carmike donated new carpeting and projection equipment to the Ellen Theater so that it could host the world premier of the film "Jurassic Park III".

On September 15, 2005, the Ellen Theatre and Rialto Theatre were purchased by a nonprofit, Montana TheatreWorks. The Russell family required that the two cinemas be sold together... Carmike Cinemas vacated the premises in April of 2008, and a massive renovation began to restore the Ellen Theater as both a stage and movie house. Local rancher Elise Donohue, the Taylor ranching family, and the Gilhousen Family Foundation provided generous donations. Martel Construction, which performed the work, did the renovations for free. The work included a refurbished ballroom, new restrooms, a reconfigured lobby, a new HVAC system, a new electrical system, refurbished plumbing, modern insulation, a new roof, and renovated dressing rooms. The renovations reduced seating slightly to 700.

In December 2008, the Ellen Theater presented its first live event in 30 years: Charles Dickens' "A Christmas Carol".

Carmike Cinemas agreed to run the Ellen Theater as a movie house after the renovation. Movies began screening there again in January 2012.

The Main Street Historic District was added to the National Register of Historic Places on December 21, 1987. The Ellen Theater is a contributing property to this district.