Born in Chicago, Illinois,[1] the son of Spencer Orville Gregory and Cora Ryer Lee,[2] Willis began his career as a child actor in the 1910s, making his screen debut for Vitagraph Studios at the age of thirteen in the title role of the 1913 drama-short Little Kaintuck.

[8][9][10] Willis is possibly best recalled for his portrayal of Dickon Sowerby in the 1919 Gustav von Seyffertitz-directed film adaptation of the Frances Hodgson Burnett novel The Secret Garden for the Famous Players–Lasky Corporation, in which he appeared opposite actors Lila Lee, Richard Rosson and Spottiswoode Aitken.

In December of that year, Motion Picture News reported that Wallis and actress Molly Malone had been signed by Robertson-Cole to appear in the company's Supreme Comedies series.

Paul Willis, who has made good in the heavier side of screen dramatics, believes he is better suited for the comedy and has now become a full-fledged fun producer.

[12]Within three months, Willis had been added to the cast of fellow recent acquisition Mae Marsh's upcoming Robertson-Cole debut, Nobody's Kid, adapted from Kate Langley Bosher's popular 1910 novel, Mary Cary, Frequently Martha.