I was just wandering if som of the characters in the Godfather movies or books were based on real historical figures, like the singer in Godfather 2.

I dont know about the singer though. But i do believe some of the cr=haracters in GF1,Gf2 and GF3 based on real characters.

Hyman Roth potrayed Meyer Lansky as he's jewish and wanted to stay in Israel as a retired and returned Jew. In real life, Lansky tried to do the same thing.

Moe Green potrayed Bugsy Siegel. Eventho the cause of his hit wasnt the same as Bugsy but he was a Vegas bigshot who got hit by NY family.

Joey Zasa potrayed John Gotti due to his "exposure" to the outside world. No surpise in that.

However, it's quite hard to detemine who is DOn Vito real life potrayal.. i want to say Carlo Gambino due to people's love and power, but what about Costello? a man with honor, reasonable and have lots of judges and politicians in his pocket.

What is impossible for me to determine is Michael Corleone's real life potrayals? who could it be? Joe Bananas because he tried to whack some of the comission?

I believe there is ONE AND ONLY ONE reallife historical person explicitly named in the entire GF Trilogy:

Fidel Castro

...in GF2 when the rebels yell "Viva Fidel" before they blow themselves up. Otherwise, they only implicitly name the generic titles of "the President" of Cuba in GF2, or the "Pope" in GF3.

Vito Corleone is a composite of real-life Dons. He's like Joe Profaci (olive oil king), Joe Bonanno (bringing his son along in the business, betrayed by an underboss), Carlo Gambino (never did time in jail), Salvatore Maranzano (defeated a rival boss by having him killed in a restaurant). But Vito's most like Frank Costello, "the Prime Minister," who had the gambling and the unions, was all-powerful politically, had all the judges in NY in his pocket, eschewed drugs, and retired after an unsuccessful assassination attempt.
Here is a rundown of other characters in the Trilogy who do--and don't fit "real life":

Close Fit:

Johnny Fontane = Frank Sinatra: Washed-up, teen-idol crooner with fealty to the Mob; role in war movie puts him back on top; sluttish, movie-star ex-wife.
Hyman Roth = Meyer Lansky: Jewish adviser to Mafia; “always makes money for his partners”; tight with president of Cuba; started out as a truck mechanic and got connected during Prohibition; fled to Israel and South America to escape Justice Dept.
Moe Green = Bugsy Siegel: Pal of Jewish adviser to Mob; “headstrong, talking loud, saying stupid things”; “city he invented was Las Vegas”; “someone put a bullet in his eye.”
Johnny Ola = Vincent (Jimmy Blue Eyes) Alo: “Sicilian messenger boy” to Lansky [N.B.: Name is an anagram.]
Joey Zasa = Joe Columbo/John Gotti: Meucci Society = Italian-American Civil Rights League; “Best-Dressed Mobster”; publicity hound; shot at Italian-American event.
Rosato Brothers = Gallo Brothers: Renegade faction in Mob family declares war on Don (Joe Profaci); Joey Gallo recruits blacks and Hispanics while in jail; “leave the gambling for last.” [N.B.: Eldest brother Larry was garroted in the back of a Brooklyn bar after-hours in 1960 and was saved by a NYC cop who happened by—the basis of the Frank Pentangeli-Rosato Brothers scene, but with roles reversed.]

Stretch Fit:

Emilio Barzini = Vito Genovese: Tried to kill rival to become Capo di Tutti Capi; attempted to make move on drugs at gangster convention (Apalachin).
Frankie Pentangeli = Joe Magliocco: Weak successor to strong Don (Profaci); beleaguered by rival faction.
Peter Clemenza = Frank Labruzzo (Bonanno Family): Top capo to Don (Bonanno) stayed loyal to son of Don (Bill Bonanno) during gang war; philosophical bent. [N.B.: Richard Castellano played Labruzzo in the TV movie, “Honor Thy Father.”]
Sal Tessio = Gaspar Di Gregorio (Bonanno Family): Top capo to Don (Bonanno) betrayed Don and son by siding with rival Don (Stefano Maggaddino) in return for being named head of his own family.
Fredo Corleone = Thomas Gambino: Weak son of Capo di Tutti Capi is passed over, given “legit” businesses to run.
Luca Brasi = Willie Moretti: Legendary strong-armer; “can do a job of murder all by himself”; “most valued friend” of Joe Bonanno and other Mob bosses; killed by the Mob (probably Vito Genovese).

No Fit:

Michael Corleone. No son ever succeeded and surpassed his father as Don. [N.B.: The two who tried--Bill Bonanno and Junior Gotti--both wound up in jail.]
Tom Hagen. No non-Italian has ever served, officially, as a Family’s consigliere.

Was Jack Woltz a take off of Jack Warner; same first name, last initial, both Jewish. Were there other similarites?

No. The real-life studio head who initially opposed Sinatra for "From Here to Eternity" was Harry Cohn. But Cohn was never muscled by the Mafia, nor was he opposed to Sinatra because Frankie stole his gal. He wanted Eli Wallach because Wallach was under contract, but eventually chose Sinatra because he was skinnier than Wallach, and thus fit Maggio's description.

I found this a little before I read this post.

At least Bill Bonnanno thinks Vito Corleone was modeled after his father.

Bonanno salutes Puzo
Family was model for bestselling 'Godfather'

By Jon Kamman
The Arizona Republic
July 3, 1999
Bill Bonanno of Tucson, whose family was the model for The Godfather and whose own memoirs as a mafioso have just been published, saluted Mario Puzo on Friday for having "set the gold standard" for books and films depicting organized crime.
"Mario had a lot of help in the sense that he grew up on the West Side (of New York City) and could put on paper what he saw and heard. He did it very masterfully," said the 66-year-old son of Joseph Bonanno, the archetype for Puzo's fictional Don Corleone.
"That piece of material has set the gold standard of this genre," Bill Bonanno said of The Godfather.
Puzo's work was "not a distorted version - never" of the mafiosi culture, said Bonanno, who objects to the term "Mafia" as a law-enforcement creation that strips the Sicilian mafioso term of its honorable meanings.
"I thought he depicted a story of tradition and a story of values and - no pun intended - really a family story," Bonanno said. "He left something that will endure."
The elder Bonanno, who was the so-called boss of all bosses of New York's five crime "families" in the 1960s, is now 94, alert and comfortable in Tucson, his son said.