Charles Logan (formerly known as President Charles Logan) is the main antagonist of Day 5 and one of the main antagonists Day 8 of 24 (alongside President Suvarov). He also appeared in Days 4 and 6, but was not antagonistic in those days (at least in Day 4; his role in Day 6 is ambiguous).
He was portrayed by Gregory Itzin.
During Day 4, Logan was the Vice-President of the United States. He was sworn in as the President under the 25th Amendment, after President John Keeler was critically injured in a terrorist attack on Air Force One. He insisted to run from the bunker, in case of further terrorist attacks.
Charles Logan was the President of the United States during Day 5, with his wife, Martha Logan, being the First Lady. He took part in assisting the recovery of Sentox Nerve Gas and several murders (not counting those died in the Nerve Gas Attacks), including Michelle Dessler, Walt Cummings and most notably, former President David Palmer. His wife, Martha, had health problems, but not as severe as they seemed. Each time she would discover evidence which may lead to the discovery of her husband's role in the Day's events (of which she was oblivious to), he would blame it on her health, and so it would seem as though she was "crying wolf" each time, when in fact she held substantial evidence. Charles even went as far as to manipulate a recorded phone call between David Palmer and her, the night before he was killed, where Palmer was trying to pre-warn Martha of the upcoming events of the day - including his own assassination. Jack Bauer, Chloe O'Brian, Aaron Pierce, Mike Novick and Martha Logan all helped assist in extracting a confession from Logan, which revealed his envolvment in the murder of Palmer and the Nerve Gas conspiracy. This forced the Attorny General to issue Secret Service to arrest Logan.
By the time of Day 6, Wayne Palmer, the brother of David Palmer, had assumed office as the President and Logan was living under house-arrest in a secret location. He claimed to have knowledge that would help Jack Bauer find Dmitri Gredenko, a terrorist who was plotting against the U.S. and was planning to detonate five suitcase nuclear devices. He was granted temporary release by Wayne Palmer, where he travelled to the Russian Consulate and confronted the Consul, Anatoly Markov. Logan was right, and Markov was in contact with Gredenko, although was reluctant to admit it and would not break when Jack interrogated him. This led him to travel to the residence of his ex-wife, Martha, whom he claimed was good friends with Anya Suvarov, the First Lady of Russia. Martha had still not forgiven him for his envolvment in the conspiracies of Day 5, and subsequently stabbed him in the shoulder, almost killing him.
Surviving Martha's attack and pardoned by President Noah Daniels, Logan was released from house arrest. During Day 8, he was reluctantly called in by President Allison Taylor, by recommendation of her chief of staff, Ethan Kanin. His relationship with the Russian Government could ultimately save the peace treaty between Russia, the U.S.A. and the Islamic Republic of Kamistan. Reluctant to accept Logan's "repented ways" at first, President Taylor did eventually grow to trust him. Although, in true Logan style, revelations involving him and both the Russians and the Americans led him to become a rogue ally to both sides. He was partly responsible for the death of Renee Walker, the lover of Jack Bauer, and so he exacted revenge on every high-ranking Russian Government official, who was complicit in her murder. Jack asked Logan to set up the assassination of Russian President Yuri Suvarov, but he was talked out of it by Chloe O'Brian. When he was revealed to be a rogue ally to both the Americans and the Russians (and destroying the concept of President Taylor's beloved peace treaty), he killed Jason Pillar, his advisor and bodyguard, and then attempted suicide by shooting himself. The attempt on his life failed and he survived with severe brain damage.