Sissi or Sisi may refer to:
People
- Empress Elisabeth of Austria (1837–1898), known as "Sisi" or "Sissi"; spouse of Franz Joseph I of Austria
- Works about Sissi
- The King Steps Out (1936), light comedy directed by Josef von Sternberg
- Sissi film trilogy with Romy Schneider:
- Sissi (film) (1955)
- Sissi – The Young Empress (Sissi – Die junge Kaiserin) (1956)
- Sissi – Fateful Years of an Empress (Sissi – Schicksalsjahre einer Kaiserin) (1957)
- Sisi (miniseries) (2009), TV film directed by Xaver Schwarzenberg, with Cristiana Capotondi
- Princess Sissi (1997), French-Canadian animated television series
- Sissi, the Anarchist Empress (Sissi Impératice), a ballet by Maurice Béjart
- Sisi – TV Series with Dominique Devenport in main role
- Abdel Fattah el-Sisi (born 1954), President of Egypt since 2014
- Ali Tneich (born 1992), known as "Sisi", Lebanese footballer
- Seyhan Soylu, known as "Sissi", Turkish television personality
- Sisi Rondina (born 1996), Filipino volleyball player
- Sisi Zlatanova, Bulgarian researcher in geospatial data
- Sisi (footballer) (born 1986), Spanish footballer Sisinio González Martínez known as "Sisi"
- Sissi (footballer) (born 1967), Brazilian football player Sisleide do Amor Lima known as "Sissi"
- Sissi Christidou (born 1980), Greek television presenter
Localities
- Sisi, Crete, a place in Crete, Greece
Other uses
- Elisabeth Delmas, nicknamed "Sissi", a character in the French animated television series Code Lyoko and its incomplete sequel series Code Lyoko: Evolution
- Sisi (drink), a Dutch fruit-flavoured beverage
- Sissi (Finnish light infantry), a specialized type of Finnish soldier
- Sissi, name given to the exoplanet HAT-P-14b, which orbits the star HAT-P-14 in the constellation of Hercules