Secondhand Lions is a 2003 American adventure/comedy film about a young boy who is sent to live with his two eccentric but mysterious great-uncles on a farm in Texas. The movie was filmed in Lockhart, Texas.

Walter (Haley Joel Osment) is sent to live with his uncles by his mother (who claims she is going to go to court reporting school), so that he can find the fortune they have supposedly accumulated. When they first arrive, Hub and Garth McCann (Robert Duvall, Michael Caine) are knee-deep in their pond, shooting at catfish with shotguns. His cousins, also strong believers in the fortune, arrive a few minutes after his mother leaves to ingratiate themselves into the good graces of Hub and Garth. They scare Walter away, and he runs to telephone his mother. He discovers that she is not actually enrolled at the school—she lied (again).

Forced to return to his uncles' farm, Walter eventually becomes used to their quirky, rather insane mannerisms and they become used to him and his shyness. While encouraging them to eat vegetables and stop shooting at visiting salesmen, he becomes aware of his uncles' mysterious past. Garth reveals to him that he and Hub were adventurers beginning in World War I.

Hub and Garth arrived in France the day that Germany invaded the country. Garth believed they should return home, but Hub proposed that they tour Europe just ahead of the invading armies. After a night of drinking and carousing in Marseilles, they found themselves on board a ship, shanghaied into the French Foreign Legion. The two brothers fought in many battles, and Hub saved Garth's life several times.

Following their Legion service, Garth became a guide in Africa, while Hub helped anybody who deserved it. Hub fell in love with Jasmine, a beautiful woman and an expert horsewoman who decided to meet him after he rescued her servant. She, however, was doomed to be a sheik's wife. Hub rescued Jasmine from the sheik, who then put a price of ten thousand gold pieces on Hub's head. Garth, disguised as a bounty hunter, turned in Hub for the reward, whereupon Hub escaped, but not before winning a duel with the sheik. Hub's parting words to the sheik were "Twice I've held your life in my hands, and twice I have given it back to you; the next time, your life is mine." He earned the other man's respect and a great deal of his gold. Later, it turns out that the sheik is the ruler of a small, oil-rich country in North Africa.

Meanwhile, the three have adventures of their own. They order circus and safari animals. One of them turns out to be an aging lioness whom Walter adopts, and names Jasmine, thereby keeping Hub from ever killing her. Hub and Garth frighten off Walter's cousins and purchase a clay pigeon thrower, a succession of ever-larger boats, and a biplane. Hub gets into a fight with several ruffians within an hour after having a heart attack, wins the fight, and gives them a lecture on what it means to be a real man. Part of the lecture:

"Sometimes the things that may or may not be true are the things a man needs to believe in the most. That people are basically good; that honor, courage, and virtue mean everything; that power and money, money and power mean nothing; that good always triumphs over evil; and I want you to remember this, that love... true love never dies. You remember that, boy. You remember that. Doesn't matter if it's true or not. You see, a man should believe in those things, because those are the things worth believing in."

Moreover, Walter finds that his uncles have been hiding their money in a room beneath their barn.

Fresh from Las Vegas (where she had been instead of at the school), Walter's mother and her (current) lover, a supposed "detective", arrive at the farm and demand to know where the money is. The lover tells Walter that Hub and Garth actually were bank robbers (and "Jasmine" their accomplice) and the fortune is anybody's for the taking. Walter decides he will believe his uncles, and the man begins to beat Walter. Jasmine attacks the "detective" and seriously wounds him, and, although the lioness dies of a heart attack in the process, she arouses enough noise to attract the attention of Hub and Garth. Walter holds Jasmine's head in his lap and says, "She was a real lion, wasn't she? There at the end. A real jungle lion. A real Africa lion," and smiles mysteriously at his uncles, his way of saying he believes in the stories of Africa.

Walter is taken away by his mother, but he decides to return to his uncles' house after she informs him she has no intention of leaving the man who nearly beat her son unconcious. He lays certain conditions on Hub and Garth: that they eat more vegetables and stop their dangerous pastimes until Walter graduates from college. Hub replies, "What do you want us to die of... old age?"

Several years later, Walter (now a successful cartoonist) comes back to discover that his uncles have flown their biplane into their barn and died. The Sheriff who informs Walter of his uncles demise passes the McCann brother's will to Walter.

While Walter reads the will ("The kid gets it all. Just plant us in the damned garden with the stupid lion.") and laughs to himself about his uncles' unique approach to life, a helicopter touches down and a Middle Eastern man steps out. He explains that he saw news of the men's deaths and their names on television and thought they might be the two courageous Americans that his grandfather (the sheik) had told him about long ago. Walter says that, yes, they were, and the two are happy to realize that the stories which had inspired them for so long were true.