Frederico "Fredo" Corleone he is the middle brother to oldest brother Santino Corleone and younger brother Michael Corleone, and son of Vito Corleone, head of a powerful Mafia family. Fredo burn in New York 1929.

Fredo was always thought of in the Corleone crime Family as the weakest of the three Corleone brothers, and therefore was given its unimportant businesses to run. He is, however, the most obedient and dutiful of the Corleone children.
In a pivotal scene in the novel and film, Fredo attempts to immediately retaliate after the attempted assassination of his father on a New York street by men working for drug kingpin Virgil Sollozzo. However, he fumbles with the gun, drops it, and is unable to return fire. He then sits on the street curb next to his unconscious father and weeps.

After Sonny's assassination and Vito's death, the younger Michael is appointed head of the family over Fredo, causing a deep rift between the two brothers which is expanded upon in Coppola's later sequels to the first film adaptation.
In the films, Fredo's lack of intelligence plays a greater role than it does in the novel. He is seen as far less mentally acute than his younger brother Michael. Michael even uses the word "stupid" when discussing his brother with family consigliere Tom Hagen.
At the Lake Tahoe party at the beginning of The Godfather Part II, Fredo is unable to control his intoxicated wife, Deanna. After she danced with another man, he furiously drags her off the dance floor and threatens to hit her. Deanna mocks him by saying that he "couldn't belt [his] momma," and that he's jealous because he's not "a real man."

In a flashback to the early days of the Corleone family, there is a scene where an infant Fredo is being treated for pneumonia.
Fredo betrays Michael when approached by Johnny Ola, an agent of rival gangster Hyman Roth. This betrayal ultimately results in an assassination attempt on Michael at his Lake Tahoe home. The film leaves unclear the details of Fredo's deal with Ola and Roth. Fredo ambiguously claimed that his goal in that deal is simply to get something for himself, on his own, and swears that he did not realize he was being used as part of a larger plot to kill his brother.
Michael discovers Fredo's role in the plot during his trip to Havana when Fredo lets it slip out that he and Johnny Ola had been in Havana together. Michael confronts Fredo later and tells his older brother, "You broke my heart." Later, when Michael is being pursued by a Congressional Committee investigating organized crime, he has a talk with Fredo and realizes that Fredo had both withheld important information from him about Roth's connection with the Committee's lawyer and is deeply resentful and jealous of Michael's role in the family business. Michael disowns and banishes Fredo from the family. Upon their mother's death, and at the urging of their sister Connie, Michael relents toward Fredo and seemingly offers reconciliation. However, it is only to draw Fredo in so as to have him murdered, something Michael did not permit while their mother was alive.

Towards the end of The Godfather Part II, Fredo and his nephew, Michael's son Anthony, develop a friendship and are to go fishing on Lake Tahoe. However, Anthony is called away by Connie, who tells him that his father wants to take him to Reno. Fredo is left alone in the fishing boat with Al Neri and he takes the boat far out onto the lake. As Fredo prays the Hail Mary, Neri shoots him in the back of the head. It is implied that Fredo's body is thrown overboard after being chained to weights. Family members outside of Michael's inner circle are told that Fredo drowned in a boating accident.
Ordering Fredo's death would haunt Michael for the rest of his life, and further alienates him from his wife Kay and son Anthony. In The Godfather Part III, Michael expresses deep remorse at ordering his brother's death years later while confessing his sins to Cardinal Lamberto who, in the film, later becomes Pope John Paul I.