Under Western Skies is a silent Western.

Gibbs is a laborer at the docks who, through his hard work and good judgment, becomes a millionaire on Wall Street. He becomes acquainted with the Van Dusens, who have lost their fortune. Mrs. Van Dusen pushes her daughter Marie into a loveless marriage with Gibbs so that the family can retain its social standing. Gibbs realizes, however, that his money cannot buy his wife's affection.

The mother of a large family is abandoned by her children and faces consignment to the poorhouse. But one of her offspring, the one no one had faith in, returns to rescue her.

Edith Sturgis, the daughter of a judge, returns from studies abroad to find her widowed father remarried. The new Mrs. Sturgis does not reveal that she has a son Dick, once unjustly jailed by Judge Sturgis, but now working as a reporter while still maintaining an association with the Brownlow gang. Quarrelling with her stepmother, Edith leaves home, meets Dick and falls in love.

A traveling theatrical troupe is stranded in a small town, and the leading ingenue, Polly, returns to her New York City hometown broke. She and her friend Bunny, desperate for a job, convince the Hawkers, a "nouveau riche" family from Kansas, that they are French and an experienced maid-and-butler team. Young Zeke Hawker is smitten with Polly, but Polly is attracted to their neighbor, a famous actor named MacGillicuddy. One night at a swanky party given by Mrs. Hawker, her jewels wind up stolen, and Polly is suspected of it. Complications ensue until Polly discovers who the real thieves are.