Charles Smithson is a fictional character from the novel "The French Lieutenant's Woman" by John Fowles. He is a young Englishman in the 1860s, engaged to Ernestina Freeman, but becomes captivated by the mysterious Sarah Woodruff, known as the French Lieutenant's Woman. Throughout the story, Charles grapples with societal expectations and his own desires, reflecting the conflicts of the Victorian era. His journey explores themes of love, freedom, and the constraints of social class, making him a complex character in a transformative period of history.