The following is a list of prominent characters featured in Mental Omega.

Allicon Allied Nations

  • USAicon Allied Commander - A U.S. commander and the player character for the Allied campaign.
  • USAicon Michael Dugan - President of the United States of America.
  • USAicon Tanya Adams - A U.S. special operations agent, equipped with a prototype laser rifle.
  • EAicon Siegfried - Protegé to Albert Einstein, brilliant scientist and CEO of SteinsTech Labs, responsible for many of the Euro Alliances technological feats, including the more modern Chronosphere.
  • PFicon Norio - Former Tokyo police officer, now a member of the Pacific Front Rocketeer Division. Holds a strong sense of right and wrong.

Sovicon Soviet Union

  • Russiaicon Soviet General - A Russian general and the player character for the Soviet campaign.
  • Russiaicon Alexander Romanov - Premier of Russia and de facto leader of the Soviet Union.
  • Russiaicon Boris - Hero of the Soviet Union, a Russian special forces operative. Led the charge into New York City but was quickly killed in action.
  • Russiaicon Volkov & Chitzkoi - Former Heroes of the Soviet Union. Left abandoned and disused in Eastern Europe after the Second Great War and reacquired and reactivated by Russia prior to the Third Great War.
  • Russiaicon Reznov & Krukov - Colonels serving under the Soviet Commander, commands military forces in the United States.
  • Confederationicon José Arcadio Morales - Former Cuban death squad commando and the deadliest assassin of the Latin Confederation.
  • Chinaicon Xiu Rong Wu - A Chinese general who leads Chinese army to invade Russia.

Yuricon Epsilon Army

  • PCicon HQicon Yuri's Proselyte - An Epsilon field commander and the player character for the Epsilon campaign.
  • PCicon Yuri - Founder and leader of Epsilon Army and its primary wing PsiCorps. A powerful and dangerous man with great ambitions.
  • PCicon Libra - One of PsiCorps' most powerful psychics, perhaps rivaling Yuri himself. Her great power can turn entire armies into dust, but her power makes her highly unstable as she suffers from violent mood swings.
  • HQicon Rahn - The ultimate result of Epsilon super soldier research. Highly intelligent being with a 'survival of the fittest' mindset.
  • SCicon Malver - Top assassin of Scorpion Cell and close friend of Rashidi. A unique psychic that solely learned and trained his psionic powers in isolation over many years. He is defected from Epsilon alongside with Rashidi later.

Foeicon Foehn Revolt

  • VOLKNET - An experimental artificial intelligence and the player character for the Foehn campaign.
  • Yunru - Chinese child prodigy. Previously singularly responsible for most of China's military technological advancements that allow them to remain competitive with the Allies. While patriotic to China she is nonetheless forced to remain in service in the Chinese army with her family being held as hostage, shows signs of mental degradation due to this and later she defected as leader of the Revolt.
  • Rashidi - Leader of Scorpion Cell, a North African terrorist/freedom fighter. He led the Scorpion Cell defected to the Foehn during the Mental Omega War.
  • HHicon Fin & Alize
  • WoCicon Eureka
  • LBicon Uragan