Sergeant 'Soap' McTavish
Sergeant 'Soap MacTavish is your character for the majority of the game. He is the newest recruit of the elite unit, the British SAS (Special Air Service).
 Sergeant Paul Jackson
Sergeant Paul Jackson is one of the members of the the United States Marine Corps. The unit he is in is the 1st Force Recon. He is led by Lieutenant Vasquez and Staff Sergeant Griggs, the latter who you meet back up with as Soap.
Sergeant Paul Jackson is the soldier you play as during the USMC search for Khaled Al-Asad. However, after storming the broadcast station during the mission Charlie Don't Surf, you discover that Al-Asad isn't there. You than discover that the United States military is pushing back Al-Asad's forces. As all this is going on, the 1st Force Recon unit are securing the area surronding War Pig, a stranded Abrams battle tank. When he and his squad are defending War Pig, Jackson is ordered by Vasquez to destroy an AA position and to mark the Marines' position with a strobe so friendly Cobra helicopters can destroy a building with enemies firing on their position. After defending until dawn, your squad decide to push forward and escort War Pig out of the target area.
 Captain Price
Captain Price is the commanding officer of the unit that Soap is in. You are introduced to the Captain in F.N.G, the first mission in the game. Listen to him, as throughout the game he shouts advice. You also get to play as the Captain half-way through the game. This is when Captain Price isn't a captain, and is undercover in Russia, following the first assassination order since the Second World War.
Price is most notably recognized for appearing in Call of Duty 2, during the British campaign. He is highly praised in Call of Duty 4 for being the same badass he was in 2. Rumors claim that he is a time traveler with no belief in shaving his awesome moustache.
Gaz is another SAS soldier under Captain's Price's command. He fights alongside the player throughout the missions in Russia. He is unique throughout the other SAS soldiers, as you are unable to distinguish his rank from subtitles or from the game. At the end of the game, he is personally killed by Imran Zakhaev when the SAS are trying to escape.
 Khaled Al-Asad
Khaled Al-Asad is a commander in an unidentified Arab country in the Arabian Peninsula. Khaled appears in the first chapter of the game as the current antagonist up until Imran Zakhaev comes in and takes the role for the next few chapters. Khaled Al-Asad is supposedly part of the "Four Horsemen", with his position as the "Second Horseman". He is the main driving force for the capturing and execution of president Yasir Al-Fulani.
 Yasir Al-Fulani
Yasir Al-Fulani is the president of an unknown Middle Eastern country. He is captured and executed by Khaled Al-Asad on national television.