Atlas is a robot who appears in all of the Astro Boy series. He is a robot with the ability to defy the rules of robotics present in the Astro Boy universe and has the ability to hurt humans. While his appearances were brief in the original 1960s series, he plays a major role in the 1980s and 2003 series.

In the 1980s series, creator Osamu Tezuka chose to develop this character's role to be more involved in the story. In this series, Atlas was built using the same blueprint for creating Astro Boy; these blueprints had been stolen by the criminal Skunk, another common antagonist of the more modern Astro Boy stories. Atlas' facial features resemble those of Astro, but his overall appearance varies greatly, with a red body and gold hair.

Rather than simply being a confused robot who carried out the commands of his human creator with no knowledge of the repercussions of his actions, he was given what was known as the Omega Factor, a device that allowed him the ability to hurt humans. Early in the series, Atlas' body was severely damaged, along with that of his beloved robotic caretaker, Livian. It was after this event that Atlas rebuilt he and Livian's bodies into the adult, warrior-like appearances that they remained in for the rest of the series. In Atlas' last apperance in the series (Atlas Forever), Astro Boy found out that he was Atlas' brother. At the end of the episode, Atlas gave up his evil ways and sacrificed himself to save the world. In the 2003 series, Atlas' name was originally Daichi, and was the robot son to Tokugawa and raised to be the first robot CEO. At first, Tokugawa cared very dearly for Daichi and even organized a birthday for him, giving him an atlas for his present (hence where he got his alias) and told them one day they could see the world from the moon, however with work getting in the way he spent less and less time with Daichi and even ignored him completely. Mr. Tokugawa believed he gave all Daichi needed in material needs, completely unaware of the lack of emotional needs to the point where Daichi rebelled against him and lead a bike gang to cause trouble while keeping the "perfect son" image in front of his father. After being rebuilt by Dr. Tenma, he used his new found powers to destroy Tokugawa Industries until Astro Boy stopped him. He later returned to destroy Tokugawa's moon base, but he had a change of heart in killing Tokugawa when he saw the earth just like his father promised him all those years ago. He often sarcastically called Astro Boy "brother", due to the fact they were both built by Tenma. In the original japanese version, Daichi was a human boy who wanted to become a painter but was verbally (and physically) abused by his father who deemed it "a useless job" and that he should only focus on being his father's successor, he died at the age of 18 in a space shuttle accident, this was cut from the english dub due to scenes of child abuse and the idea that it might be "too depressing" for the american audience