| A Nymph by a Stream | |
| Medium: | Oil on canvas |
| Artist: | Pierre-Auguste Renoir |
| Year: | 1869–70 |
| Height Metric: | 66.5 |
| Width Metric: | 124 |
| Museum: | National Gallery |
| City: | London |
A Nymph by a Stream is an oil painting of 1869–70 by Pierre-Auguste Renoir which is held in the collection of the National Gallery, London. The painting portrays Renoir's 21-year-old model and lover, Lise Tréhot, who featured in over twenty of his paintings during the years 1866 to 1872.
Unusually, the painting is a combination of a classical depiction of a naiad or river nymph reclining by a stream and the recognisable portrait of an actual person.