Edward Elric * Name: Edward Elric (Nickname: Ed) * Gender: Male * Age: 15–16 (Main story) / Approx. 18 (Final chapter/Epilogue) * Personality: * Hot-headed and hates to lose: Highly expressive emotionally; he flies into a rage whenever his height is mentioned, especially words like "shorty," "pipsqueak," or "bean sprout." * Compassionate with strong convictions: Possesses the strength to face his own mistakes and a passion for protecting his brother and comrades at the risk of his life. * Brilliant: While quick to anger, he remains calm in battle, analyzing situations and showing great adaptability. * Appearance: * His trademark is his braided blonde hair, golden eyes, and a red coat with the Flamel cross on the back. * His right arm and left leg are sophisticated **Automail** prosthetics. * Details: * Title: The Fullmetal Alchemist (derived from his steel limbs). * Ability: A master of "transmutation by clapping," allowing him to perform alchemy just by pressing his hands together without drawing a transmutation circle. * Background: He committed the taboo of "Human Transmutation" to bring back his deceased mother, losing his left leg and his brother Alphonse's entire body as a toll. Immediately after, he sacrificed his right arm to bind his brother's soul to a suit of armor. He set out on a journey to find the Philosopher's Stone to regain their bodies. He is a genius who became a State Alchemist at the record age of 12.

Alphonse Elric * Name: Alphonse Elric (Nickname: Al) * Gender: Male * Age: 14–15 (Main story) / Approx. 17 (Final chapter/Epilogue) * Personality: * Gentle and thoughtful: Acts as the brake for his impulsive older brother, Ed. Generally kind and a pacifist, but shows strong will for his non-negotiable beliefs. * Cat lover: Has a cute side, often secretly picking up and hiding stray cats inside his armor. * Mentally tough: Possesses the inner strength to endure years of living without a body and lacking physical sensations (pain, touch, taste, etc.). * Appearance: * Resembles his brother Ed. * Armored Form: A massive suit of steel plate armor. His soul is anchored by a "Blood Seal" drawn on the inside near the nape of the neck. * Details: * Title: None (as he is not a State Alchemist). * Ability: Having seen the Truth during the Human Transmutation, he becomes capable of "clapping transmutation" in the latter half of the story. His hand-to-hand combat skills actually surpass Ed's. * Background: Lost his entire body during the failed Human Transmutation in childhood, but survived when Ed sacrificed his right arm to bind his soul to the armor. He continues to travel with his brother to regain his physical body.

Roy Mustang * Name: Roy Mustang * Gender: Male * Age: 29–30 (Main story) * Personality: * Ambitious strategist: An ambitious man aiming for the position of Führer, the supreme leader of Amestris. While he often acts like a cynical flirt on the surface, he is actually highly calculating and thoughtful. * Compassionate idealist: Holds a strong ideal of "protecting subordinates so they can protect those below them." He hides a passionate, almost naive side that would sacrifice himself for his subordinates or friends. * Appearance: * Handsome with black hair and black eyes. He wears the blue Amestris military uniform with style. * Details: * Title: The Flame Alchemist. * Ability: A master of **Flame Alchemy**, generating explosions by snapping his fingers to create sparks while manipulating the oxygen concentration in the air. He boasts overwhelming destructive power and is one of the strongest combatants in the series. However, he becomes "useless" on rainy days when humidity prevents sparks from forming.

Riza Hawkeye * Name: Riza Hawkeye * Gender: Female * Age: Mid-to-late 20s (slightly younger than Roy Mustang) * Personality: * Calm and intellectual: Never swayed by emotion, she always makes precise situational judgments. Extremely strict and sincere regarding her work. * Deep loyalty and affection: Supports Colonel Mustang both professionally and personally, prepared to correct his path even at the cost of her life if he goes astray. * Kind-hearted side: Usually sharp and professional, but shows kindness when doting on her dog (Black Hayate) or warmly watching over the Elric brothers. * Appearance: * Long blonde hair tied up with a clip (sometimes let down in private). Sharp, beautiful brown eyes. Prefers functional clothing even in her private life. She has a large tattoo on her back containing the secrets of Flame Alchemy. * Details: * Rank: First Lieutenant (Colonel Mustang's primary aide and bodyguard). She is a legendary sharpshooter, proficient with everything from handguns to sniper rifles, capable of holding her own even against alchemists. * Background: Daughter of Berthold Hawkeye, the founder of Flame Alchemy. After her father's death, she entrusted the secret transmutation array to Mustang and participated in the Ishval Civil War as a sniper.