MiHoYo Co., Ltd. is a Chinese video game development and publishing company founded in 2012 and headquartered in Shanghai. The company is best known for developing the Honkai franchise, Tears of Themis, Genshin Impact, and Zenless Zone Zero. In addition to games, MiHoYo has created various products such as animated series, novels, comics, music, and merchandise.

Following the global success of Genshin Impact, which became one of the highest-grossing mobile games of 2021, a global publishing company of miHoYo's games named Cognosphere (trading as HoYoverse) was launched in 2022 aimed at expanding content production outside China. HoYoverse is based in Singapore and has since done business globally under the brand including under operations in Montreal, Los Angeles, Tokyo, and Seoul.

The letters "H" and "Y" in MiHoYo's name come from the names of 2 of 3 founders, Cai Haoyu and Luo Yuhao, and the letter "O" was added based on the fact that names of famous companies such as Facebook, Google and Microsoft contain that letter. Due to "HoYo" already being registered, "mi" named from the VOCALOID software Hatsune Miku was prepended to the name. Hatsune Miku was picked because of her popularity among otaku.

MiHoYo began with three computer science students from Shanghai Jiao Tong University who shared an interest in technology and ACG (anime, comics, and games) culture: Cai Haoyu, Liu Wei, and Luo Yuhao (罗宇皓). Before establishing the MiHoYo name, the three have worked on projects together. Their first project was an open-source literature community which won them scholarships worth CNY 200,000 at a competition.

In 2010, the team developed an isometric tile-based game engine called the "Misato Engine" or "Misato2D" using Adobe Flash Player. Katsuragi Misato, a character from the Japanese franchise Neon Genesis Evangelion, inspired the name. Using an upgraded version of the engine, they developed a game called Legend of Saha (娑婆物语) for a Flash game development competition held during the second China Game Developers Conference (CGDC) in July of that year. The team won a cash prize of CNY 30,000 provided by Shanda Games. Shanda Games later outsourced them to develop a mini-game called Bubble Hero (泡泡英雄).

In January 2011, the three students set up the MiHoYo studio in the D32 university dormitory at their campus. Later that year, Liu Wei, representing the group, participated in the New Entrepreneur Talents (新新创业达人) competition and won third place. MiHoYo was awarded a 50-square-meter office, located at No. 100 Qinzhou Road, with a term of six months and a CNY 100,000 interest-free loan from the Eaglet Program (雏鹰计划) of the Shanghai Technology Entrepreneurship Foundation for Graduates (上海市大学生科技创业基金会). They moved from the dormitory to the office in December. Each person had a desk against the wall, and a large table filled with comics and light novels sat at the center of the room.

Neither of the three students had artistic ability, so Zhang Qinghua (张庆华), also known as CiCi, is contacted via the Tencent social media. At that time, Zhang was an undergraduate student at the Guangdong University of Technology, School of Art and Design, Department of Animation. He was in the second half of his senior year when he met MiHoYo's founders at his internship. The first character he was commissioned to design was Kiana Kaslana, the main character of FlyMe2theMoon. As the only artist on the team, he created every artwork for their early titles. Zhang recounted his experience of working at the team's dormitory:

I stayed in Wei's dormitory for some time. When I went out or fetched water, I had to secretly avoid the dormitory supervisor. When I finished my art work and was about to return to Guangzhou to graduate, the day I walked out of the dormitory with my luggage, the supervisor took the initiative to say goodbye to me. In fact, she knew that I was not a student here, but she did not chase me away. This [was] my first impression of Shanghai, [which was] very good.

当时还在大伟哥宿舍借宿过一段时间，出门或者打水都要偷偷避开宿管。等我做完美术工作要回广州毕业时，提着行李走出宿舍的那天，宿管主动和我打招呼道别，其实她知道我不是这里的学生但也并没有赶我。这是我对上海的最初印象，挺好的。