| Kei Saito | |
| Native Name: | 齋藤慧 |
| Native Name Lang: | jpn |
| National Team: | Japan |
| Ethnicity: | Japanese |
| Citizenship: | Japan |
| Birth Date: | 20 February 1996 |
| Birth Place: | Japan |
| Residence: | Sagamihara, Kanagawa, Japan |
| Alma Mater: | Kanagawa University |
| Occupation: | Short-track speed skater Student |
| Height: | 161 cm |
| Weight: | 55 kg |
| Other Interests: | Fishing |
| Country: | Japan |
| Sport: | Speed skating |
| Position: | Reserve |
| Event: | Men's 500 metre Men's 1,000 metre Men's 1,500 metre Men's 5,000 metre relay |
| Event Type: | Short-track |
| Coach: | Jonathan Guilmette Saburo Imai |
is a Japanese short-track speed skater.[1] He is known for being the first case of doping at the 2018 Winter Olympics after he was found to have been using acetazolamide.[2]