Systemic juvenile rheumatoid arthritis (JRA) is a type of JRA in which a child experiences a very high fever and, in some cases, a rash, on a daily basis. Joint pain or swelling may appear a few weeks or months after the fevers begin.

Systemic juvenile rheumatoid arthritis is the least common yet potentially most serious type of JRA. Organs such as the heart, lungs, liver, spleen, or lymph nodes may eventually be affected. Episodes of whole-body (systemic) symptoms can last for weeks to years and can come and go during the first years of the disease. About half of children with systemic JRA recover completely after a few years.

Systemic juvenile rheumatoid arthritis is sometimes also called Still's disease.