Across the River and Into the Trees is a novel by American writer Ernest Hemingway, published by Charles Scribner's Sons in September 1950. Prior to publication the novel wasserialized in Cosmopolitan magazine. The title is derived from the last words of Confederate General Thomas J. (Stonewall) Jackson.

The opening of the novel is set in Trieste, on the last day in the life of the protagonist, Colonel Richard Cantwell. Much of the novel is a protracted flashback, during which Cantwell reminisces about a young Venetian woman, Renata, and his life as a soldier during the war. An important theme in the novel is that of death and how one faces death. One biographer and critic sees a parallel between Hemingway's Across the River and Into the Trees and Thomas Mann's Death in Venice. Generally critics agree the novel is built upon successive layers of symbolism. As in his other writing, Hemingway employs the style known as the iceberg theory, in which much of the substance of the work lies below the surface of the plot itself.

The novel was written in Italy, Cuba and France. While visiting Italy, Hemingway met a young woman with whom he had a protracted relationship which has been defined as a father-daughter relationship. The woman, Adriana Ivancich, became the model for the female character in the novel. With some exceptions, Across the River and Into the Trees was poorly received, and was the first of Hemingway's novels to receive consistently bad press. In the years since its publication, however, some critics have come to believe it is an important addition to the Hemingway canon.