Steampunk is a subgenre of science fiction and a retrofuturistic subculture that incorporates technology and aesthetic designs inspired by 19th-century industrial steam-powered machinery. The aesthetic is typically set in an anachronistic Victorian era or a fantastical alternate history version of it, posing the question of what the world might look like if steam power had remained the dominant technology. This results in a style that combines ornate Victorian elegance with intricate and visible mechanical elements such as exposed gears, cogs, pipes, and brass fittings. The term itself was coined in a 1987 letter by author K.W. Jeter as a humorous, tongue-in-cheek reference to Cyberpunk to describe the speculative fiction works being written at the time.

While the term is modern, the roots of Steampunk can be traced to 19th-century scientific romance writers like Jules Verne and H.G. Wells, whose stories explored advanced technology through the lens of their time. These authors are considered foundational precursors, providing the seeds for the genre. The visual aesthetic of modern Steampunk began to emerge in the mid-20th century, particularly in film and television that romanticized a Victorian vision of the future. The 1960s television series The Wild, Wild West is often cited as an early example of the blend of historical setting and futuristic technology that would define the aesthetic.

The literary genre was formally established in the 1980s. In 1987, author K.W. Jeter was looking for a collective term for the Victorian-era speculative fiction being written by himself (Infernal Devices), Tim Powers (The Anubis Gates), and James Blaylock. He jokingly suggested "steampunks" in a letter to Locus Magazine , and the name stuck. The genre was further solidified with the publication of William Gibson and Bruce Sterling's 1990 novel The Difference Engine , which is considered a seminal work. Beginning in the mid-2000s, Steampunk grew from a literary genre into a broader subculture and maker movement, with a focus on fashion, crafting, music, and community events.

Steampunk's visual style is characterized by a combination of Victorian-era elegance and industrial functionality. The aesthetic heavily features materials like brass, copper, polished wood, leather, and glass, while avoiding plastics and other modern synthetics. Key motifs include exposed gears and cogs, analog clocks and dials, steam pipes, boilers, and intricate clockwork mechanisms. These elements are applied to everything from machinery and vehicles, such as airships and steam-powered automatons, to everyday objects.

Steampunk fashion is based on the silhouettes of the Victorian and Edwardian eras. Common attire includes suits with waistcoats, top hats, corsets, bustles, and long dresses. These historical garments are then customized with anachronistic technological and industrial elements. Accessories are crucial to the look and often include brass goggles, pocket watches, and jewelry incorporating mechanical parts like cogs and gears. The fashion is largely a product of the DIY ethos, with individuals modifying and creating their own unique outfits.

As a subculture, Steampunk is often defined as a reaction against modern society's trends. It functions as a counterculture that rejects the sleek, minimalist, and often incomprehensible technology of the present day in favor of intricate, ornate, and mechanically transparent designs. It also stands against modern "throwaway society" by valuing craftsmanship, quality, and durability. A central tenet is a Do-It-Yourself (DIY) attitude, which encourages participants to create their own clothing, accessories, and props, fostering a sense of ingenuity and self-sufficiency.

Steampunk's relationship with history is one of romanticism rather than accuracy. It draws on a perception of the Victorian era shaped by historical films and modern sensibilities, consciously ignoring the period's harsh realities such as disease, oppression, and social inequality. The community is noted for being inclusive and welcoming, valuing politeness, creativity, and individuality over aesthetic purity or historical precision.

Steampunk's influence extends across literature, film, video games, and music, with many works either defining the genre or heavily borrowing its aesthetics.

Beyond the foundational works of Verne and Wells and the genre-defining novels of Jeter, Powers, and Gibson & Sterling, modern Steampunk literature is a broad field. Popular examples include Scott Westerfeld's young adult series Leviathan , which imagines a World War I fought between the mechanical German Clankers and the bio-engineered British Darwinists, and Gail Carriger's Parasol Protectorate series, which blends Steampunk with urban fantasy.

The aesthetic has been prominently featured in film and animation. Terry Gilliam's Brazil (1985) is an early example of a similar retrofuturistic style. Other significant films include The City of Lost Children (1995), Wild Wild West (1999), and the animated Disney film Treasure Planet (2002). Studio Ghibli's Howl's Moving Castle (2004) and Katsuhiro Otomo's Steamboy (2004) are notable anime examples. In television, recent series like Carnival Row and The Nevers have explored Steampunk worlds.

The interactive nature of video games has made them a popular medium for exploring Steampunk settings. The BioShock series, particularly BioShock Infinite , is heavily influenced by the aesthetic. Other key titles include the stealth-action game Dishonored , the RPG Arcanum: Of Steamworks and Magick Obscura , and the puzzle game series Professor Layton .

A dedicated music scene has also developed around the subculture. Bands like Abney Park, which shifted from a gothic to a Steampunk identity in 2005, and the automaton-themed musical troupe Steam Powered Giraffe are central to the movement. Their music often incorporates narrative elements and themes consistent with the genre's literary and visual worlds.