The GTA series has a large cast of characters, with many recurring characters and a few main protagonists across the series.
Characters List
Here is a list of some of the main characters from the series, along with some information about each one:

Claude: The protagonist of the first game in the series, Grand Theft Auto. Claude is a silent protagonist who is trying to escape from Liberty City after being betrayed by his girlfriend.

Carl Johnson (“CJ”): The protagonist of Grand Theft Auto: San Andreas, He is a member of the Grove Street Families gang who returns home to Los Santos after his mother is killed. He becomes embroiled in the city’s criminal underworld as he tries to rebuild his gang.

Johnny Klebitz: A supporting character in The Lost and Damned, a DLC for Grand Theft Auto IV. He is the vice president of The Lost, a biker gang.

Luis Fernando Lopez: A supporting character in The Ballad of Gay Tony, another DLC for Grand Theft Auto IV. He is the bodyguard and assistant of Yusuf Amir, a wealthy businessman.

Michael De Santa: The three main characters in Grand Theft Auto V, they are all criminals with their own unique stories and abilities. Michael is a retired bank robber, Franklin is a young street criminal, and Trevor is a violent psychopath.

Niko Bellic: The protagonist of Grand Theft Auto IV. He is an Eastern European immigrant who comes to Liberty City to pursue the American Dream, but gets caught up in the city’s criminal underworld.

Tommy Vercetti: The protagonist of Grand Theft Auto: Vice City. He is a mobster who was sent to Vice City to establish his criminal empire after a drug deal went wrong

Victor Vance: A supporting character in Grand Theft Auto: Vice City Stories, he is Tommy’s brother and a soldier in the United States Army who is sent to Vice City on a covert mission.