Mad Barbarians is a Japanese illustration and design unit formed in 2000 by illustrator Katsuya Saito and graphic designer Masumi Ito, who was formerly known as Masumi Ito. The duo operates with the creative concept of "mad, pop, rock, cute, and stupid," and is recognized for a distinctive illustration style that blends pop art with rock sensibilities. Their work extends beyond anime into character design, apparel, vinyl toys, and commercial packaging.

In 2008, Mad Barbarians created the original property Unko-san - Tsuiteru Hito ni Shika Mienai Yōsei, which centers on a fairy visible only to fortunate people. This property was adapted into a television anime in 2009, which aired on Kansai Television. The anime garnered attention in newspapers and on television, leading to a wide range of merchandise and a DVD release. The same unit is also credited for the anime Unko-san Junjō-ha, another entry in the Unko-san series. Beyond this series, the duo is known for original vinyl figures such as GUS CURRY & SPICE, which was released by an overseas manufacturer and gained popularity internationally.

Recurring themes in their artistic identity include irreverent humor, bold graphic lines, and a fusion of cute character design with edgy or rock-inspired motifs. Their portfolio includes collaborations with major brands such as Levi's Taiwan, Takara Tomy Arts, Taito, Sanrio for Hello Kitty collaborations, and New Japan Pro-Wrestling. They have also designed products for the Japanese market including gashapon figures, apparel, and beverage labels. In 2010, they launched an original apparel brand called BARBARO MATTO. The unit has maintained a significant presence in the designer toy and streetwear scenes while contributing to anime as original creators.