Ultraman (ウルトラマン, Urutoraman) is a Japanese superhero introduced in the 1966 TV series Ultraman. He is the first tokusatsu hero launched by the Ultra Series and by Tsuburaya Productions. The character produced the Kyodai Hero genre with shows such as Godman and Iron King.

Following Ultraman's success, Tsuburaya created another Kyodai hero series still as part of their Ultra Series project, Ultraseven. While both series shared the same genre with very similar heroes, there was originally no relationship between the two. It was not until Return of Ultraman was created four years later in 1971 that both Ultraman and Ultra Seven came together into the same story. This event cemented Tsuburaya Productions' decision to have the Ultra Series continue to follow the trend of focusing on an Ultraman with each new entry. The original red-and-silver giant hero himself enjoyed a long series of popularity and has continued to appear in various works in the Ultra Series. Apart from that, he also has a lot of popularity trademarks that make him memorable to this day: his Color Timer, the Spacium Ray stance, and his famous cry "Shuwatch" (シュワッチ, Shuwatchi).

In the series, Ultraman's grunts and his iconic shout "Shuwatch" were provided by Masao Nakasone (中曽根雅夫, Nakasone Masao), who would later voice him as an actual character in episode 33 during his fight with Alien Mefilas. His dialogue in episodes 1 and 39 was provided by Hisashi Kondō (近藤久, Kondō Hisashi) while in episode 15, he was voiced by Koji Ishizaka (石坂 浩二, Ishizaka Kōji), the narrator of episodes 1 to 19. In subsequent appearances, Ultraman reuses Masao's grunt while his voice is provided by Susumu Kurobe (Shin Hayata's actor) or just simply speechless during the screen time. Ultraman's suit actor was Bin Furuya (古谷敏, Furuya Bin) during the original season. He would later go on to portray Ultra Guard member Amagi, one of the characters in the later series, Ultraseven. Ultraman appeared in later works of the Ultra Series played by various voice and suit actors. Although Susumu Kurobe did reprise his role as Hayata or provided the voice of Ultraman himself at times (though his grunts were still reused from the late Masao Nakasone) but there are other occasions where he was voiced by other voice actors.

In Japan, the Ultraman brand generated $7.4 billion in merchandising revenue from 1966 to 1987. Ultraman was the world's third top-selling licensed character in the 1980s, largely due to his popularity in Asia.

Writer Tetsuo Kinjo originally envisioned an intergalactic reptilian creature named Bemular to be the character that would become Ultraman. The creature could grow in size to 164 feet, with the design being a cross between Garuda and Tengu. The original treatment was that Bemular would assist an attack team against threats such as other Kaiju. However, worries rose that viewers would be confused upon which monster to root for. Ultraman's memorable design was done by Tohl Narita and clay sculptor Akira Sasaki, with the grey alien concept in mind. Three Ultraman body suits were created for the show, all of which were based on the size of suit actor Bin Furuya. A lot of improvements to Ultraman's design were made during the series' progression. The first suit was known as Type A (episodes 1 to 13), followed by Type B (14–29), and finally Type C (30 and subsequent episodes).

The Type A suit had its mask created from fibre-reinforced plastic (FRP) and coated with latex, giving Ultraman a "wrinkled" face. The mask was originally intended to have a mouth-opening mechanism but the latex-coating prevented such functions. Bin Furuya mentioned that Type A fitted him poorly and it forced him to hunch a bit. Followed by the deterioration of the Type A suit, Type B was made later on. Its mask removed the mouth-opening mechanism concept and latex coating, opting instead for a full FRP cover. Some of the staff in the series were not made aware of the changes that were made and were surprised by Ultraman's face having a sudden change from an alien-like face to an "iron mask" looking face. The Type B mask even had its jaw feature more narrow and sharpened compared to the Type A design. Type B was also bigger compared to Type A and according to Furuya; "it was better fitting, and had padding so it looked like Ultraman was more muscular". The Type C suit was nonetheless an improved variant of Type B, which featured slight changes in the facial positions of the eyes, mouth and ears. The rest of the body of each suit was a painted wetsuit, a design choice that was previously used for the Kemur Man from Ultra Q, the series that preceded Ultraman. Type A's boots were derived from modified Jika-tabi, Type B variants were pointed shoes with hidden zippers and Type C were red leather shoes painted silver.

Due to being made with wet suits and latices, the suits were incapable of sustaining long periods of time. What happened to each of the suits follows:

According to Furuya, the original Ultraman suit was destroyed, but this has not been confirmed.