Jefferson Smith is a fictional character from the 1939 film Mr. Smith Goes to Washington, directed by Frank Capra. He is portrayed by actor James Stewart as an idealistic and naive young man who is appointed to the U.S. Senate. Smith's character embodies themes of honesty, integrity, and the struggle against political corruption. In the film, Jefferson Smith faces challenges as he attempts to bring about change in a system filled with deceit and manipulation. His journey highlights the importance of civic engagement and the power of one individual to make a difference in the political landscape.