Indre Østfold is a municipality in the region of Indre Østfold in Østfold county. The municipality was established on 1 January 2020 by a merger of the five municipalities Askim, Eidsberg, Hobøl, Spydeberg and Trøgstad. The municipality has a total population of just under 45,000, spread out over several small towns such as Askim, Mysen, Spydeberg, Skjønhaug and Tomter. This is quite unusual for Norwegian municipalities.

• Haakon IV of Norway (1204 in Eidsberg – 1263), King of Norway 1217–1263
• Jacob Nicolai Wilse (1736–1801), parish priest in Spydeberg and Eidsberg
• Nils Christian Frederik Hals (1758 in Eidsberg – 1838 in Trøgstad), lieutenant colonel, commanded and surrendered Fredrikstad Fortress
• Olai Pedersen Wiig (1802 in Trøgstad – 1887)‚ politician, mayor of Trøgstad 1844 to 1847
• Halvor Heyerdahl Rasch (1805 in Eidsberg – 1883), zoologist and academic
• Thea Foss (1857 in Eidsberg – 1927), founded Foss Maritime, the real-life inspiration for Tugboat Annie
• Emma Hjorth (1858 in Hobøl – 1921), founder of the Emma Hjorth Home [no], the country's first large institution for people with intellectual disabilities
• Nordal Wille (1858 in Hobøl – 1924), botanist
• Adam Hiorth (1879 in Spydeberg – 1961), barrister and playwright
• Olga Bjoner (1887 in Askim – 1969), journalist and Nazi politician
• Jørgen Adolf Lier (1906–1994), politician, mayor of Askim several times
• Anton Skulberg (1921–2012), scientist and politician, mayor of Spydeberg 1963–1967
• Dagfinn Føllesdal (born 1932 in Askim), Norwegian-American philosopher
• Oddbjørn Engvold (born 1938 in Askim), astronomer
• Erik Mollatt (born 1941), businessperson, lives in Hobøl

• Enevold Thømt (1878 in Askim – 1958), decorative painter inspired by Norwegian folk art
• Kirsten Sørlie (1926 in Askim – 2013), actress and stage director
• Vidar Sandem (born 1947 in Trøgstad), actor, playwright and theatre director
• Jan Garbarek (born 1947 in Mysen), jazz saxophonist
• Cecilie Løveid (born 1951 in Mysen), novelist, poet, playwright and writer of children's books
• Rune Rudberg (born 1961 in Trøgstad), singer of dansband music
• Lene Alexandra (born 1981 in Trøgstad), singer, TV personality and model
• Jon Audun Baar (born 1986 in Tomter, Hobøl), jazz drummer.

• Brothers Henning Solberg (born 1973) and Petter Solberg (born 1974), former professional rallycross drivers, born in Askim and grew up in Spydeberg
• Jens Kristian Skogmo (born 1987 in Askim), footballer with 285 club caps
• Vibeke Skofterud (born 1980 in Askim), Olympic Gold medallist in cross-country skiing

• Media related to Indre Østfold at Wikimedia Commons