Count Luchino Nefaria is a supervillain appearing in American comic books published by Marvel Comics. Created by Stan Lee and Don Heck, the character first appeared in The Avengers #13 (February 1965). Count Nefaria is a socialite and crime boss who operates an international crime syndicate known as the Maggia.

Count Nefaria debuted in The Avengers #13 (February 1965), created by Stan Lee and Don Heck. He appeared in the 2011 Moon Knight series. He appeared in the 2018 Marvel Action Avengers series. He appeared in the 2023 New Mutants Lethal Legion series.

Luchino Nefaria is a wealthy Italian aristocrat and traditionalist that also desires greater wealth and power, driving him to join the Maggia criminal organization. The recently formed Avengers superhero team, however, thwart many of his plans and force a direct conflict, so Nefaria lures the Avengers to his castle on the pretense of a charity event, and places the group in suspended animation, using images which threaten to take control of America. After he releases them, the Avengers become suspicious of him after hearing they are wanted and they cannot remember what happened at the castle. They go to the castle, however nearly all of them are paralyzed by Nefaria's gas. Meanwhile, the Teen Brigade were captured by Nefaria, and when they tried to contact the Avengers were thrown in a dungeon which would place them into suspended animation if they touched the walls. Captain America gets into the castle without touching the ground, other Avengers, or walls, and freed the Teen Brigade, who gave the antidote to the Avengers. Captain America was also paralyzed, and with his hands and feet attached to ropes he was suspended between floor and ceiling, where Nefaria mocked him, saying he would be a hero for capturing him. However, Iron Man then burst through the wall. Neferia was defeated and deported after an officer heard him confess to being in the Maggia. In retaliation, Nefaria then unsuccessfully attempts to destroy Iron Man, and then suffers yet another defeat when stopped by the mutant X-Men team.

Nefaria reappears several years later and attempts to take control of the United States base NORAD, but is stopped by the X-Men once again. Nefaria attempts to escape in a plane which is attacked by the X-Man Thunderbird. The plane then explodes, killing Thunderbird and injuring Nefaria.

Now virtually destitute and discredited, Nefaria hires the supervillains Living Laser, Power Man and Whirlwind to form the second Lethal Legion. The group rob several banks, and unwittingly finance an experiment Nefaria has created in a bid to become superhuman. Employing the former scientific adviser to Heinrich Zemo, Nefaria devises a means of temporarily amplifying the abilities of the Lethal Legion, and then sends them into combat against the Avengers. The effect, however, is temporary and once defeated their combined abilities are drained by Nefaria who possesses them magnified a hundredfold. After a long and protracted battle, Nefaria is finally defeated.

Nefaria is kept in isolation and under observation by the Avengers, and it is discovered that the process to empower him makes Nefaria immortal but vulnerable as his body reconfigures itself. Whitney Frost, also known as Madame Masque and the daughter of Nefaria, attempts to find a cure for what is believed to be his deteriorating condition. She hires the Ani-Men to attack Avengers Mansion and free her father. While battling Iron Man, Nefaria's life-support system is severed and his weakened form is crushed by a stored Jupiter Landing Vehicle. Nefaria briefly reappears some time later as a corpse reanimated by the Grim Reaper. Grim Reaper directs Nefaria to attack the Avengers, but loses control soon afterwards and Nefaria dies once again.

Nefaria eventually reappears, but in an ionic humanoid form, and constantly requires ionic energy to sustain his existence. He battles Iron Man and later Captain America and Ka-Zar in the Savage Land as he attempts to find sources of energy. Nefaria then plans to detonate an ionic bomb, which will transform millions of people into an ionic state which he can then control, perceiving it as the best way to guarantee that he receives the respect that he feels he deserves. Nefaria gains control of the ionic heroes Wonder Man and Atlas who he intends to use to kill the Avengers, but he is stopped by the combined efforts of the Avengers, fellow superhero team the Thunderbolts and Madame Masque, Masque using a weapon she had developed to disrupt Nefaria's own ionic energy. He is next seen as an inmate of the Raft, a prison for supervillains, and escapes when Electro stages a mass breakout.

Following the "Siege" storyline, Madame Masque sought out her father to help the Hood after Loki took back the Norn Stones. The New Avengers capture John King (Hood's cousin) and use him to track the Hood and Madame Masque. After a battle with Count Nefaria, they capture the villains and bring all four of them to Maria Hill to place them under arrest.