Nance O'Neil (also Nancy O'Neil) (October 8, 1874 - February 7, 1965) was an American actress of stage and silent cinema of the early 20th century, dubbed the American Bernhardt.

O'Neil was born in Oakland, California, as Gertrude Lamson to George Lamson and Arre Findley. When she decided to become an actress, her religious father, an auctioneer, denounced his daughter in church for going on the stage and asked the congregation to pray for her.

An unidentified critic in The New York Times wrote of O'Neil's talents in 1908, stressing the positives of her performances while warning of the actress' drawbacks. "There is no actress on the stage at present who has a more remarkable gift for emotional expression, nor is there a single one who has been more lavishly endowed by nature with the physical gifts which enter into the equipment of great actresses", he wrote. "Miss O'Neil has a kind of massive beauty, and she is not without much natural grace. Her voice is a splendid organ, rich and deep, with plenty of color and sweetness. There are moments when it is expressive of deep feeling. But there are more extended periods when it is pitched in monotonous cadences, during which the actress speaks seem to be delivered without a hint of genuine feeling or understanding, when, in short, she is simply an actress giving voice to words that she has conned and learned by rote and delivered in a sort of phonographic manner without a suggestion of the thought behind them".