Alex the Lion is one of the main characters of the Madagascar series of films. The second Madagascar film, Escape 2 Africa, reveals that Alex was born with the name Alakay. He is the son of Zuba and Florrence, the alpha lions of their pride. Alex is a lion who is best friends with a zebra named Marty, and the two are also good friends with a hippo named Gloria and a giraffe named Melman. Alex is the self-proclaimed leader of his group, and prefers dancing over fighting. He's self-absorbed and sometimes fails to see the problems of others above his own.

Alex's predatory nature coming out is a source of conflict for much of the first movie, though ultimately he cares about his friends and tries to isolate himself during the movie to keep them safe. In the second movie, he reunites with his parents after being captured and brought to New York Zoo at a young age, but is cast out of his pride after failing the initiation when Zuba's rival, Makunga, manipulates Alex into choosing his opponent to be Teetsy, a huge, muscular male lion. The initiation involves fighting, something Alex prefers not to do. In the third movie, he develops something of a relationship with a female jaguar named Gia.

Alex is voiced by Ben Stiller in all his main-series film appearances, including in the short features Merry Madagascar and Madly Madagascar, but in his cameo appearance in the The Penguins of Madagascar TV Series, he is voiced by Wally Wingert instead. In All Hail King Julien he is voiced by Crispin Freeman.