Eirene /aɪˈriːniː/, also Jupiter LVII and originally known as S/2003 J 5, is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003^[3][4] but was then lost.^[5][6][7][8] It was recovered in 2017 and given its permanent designation that year.^[9]

Eirene is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 23,974,000 km in 743.88 days, at an inclination of 166° to the ecliptic (167° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.307.

It belongs to the Carme group, made up of irregular retrograde moons orbiting Jupiter at a distance ranging between 23 and 24 Gm and at an inclination of about 165°.

The moon was named in 2019 after Eirene (Εἰρήνη), the daughter of Zeus and Themis and the goddess of peace in Greek mythology; the name originated from a naming contest held on Twitter with sixteen tweets suggesting the name, most significantly by users Quadrupoltensor (@Quadrupoltensor) who first suggested the name and PaulR (@PJRYYC).^[10][11][12]