Sif is a Norse goddess and the wife of Thor.
Sif or SIF may also refer to:
People Sif Atladóttir (born 1985), Icelandic footballer Sif Ríkharðsdóttir, Icelandic academic Sif Ruud (1916–2011), Icelandic actress Sif Rykær (born 1988), Danish footballer Sif Saga (born 1997), Icelandic model
Characters Sif (character), the Norse goddess as portrayed in Marvel Comics Sif (Marvel Cinematic Universe), the character's portrayal in the MCU Sif (Dark Souls), a character in the video game Dark Souls
Places Sif, Yemen Sif Glacier, Greenland Sif Island, Antarctica
Government and politics State Secretariat for International Finance, of the Government of Switzerland Society for Individual Freedom, a British association promoting individual freedom Somali Islamic Front, also known as Jabhatul Islamiya Strategic Innovation Fund, a program of the Government of Canada Syrian Islamic Front Statutes in Force, the 4th revised edition of the statutes in the United Kingdom
Science and technology Italian Physical Society () Safety instrumented function Schools Interoperability Framework, a data-sharing specification Selective Identification Feature, used to identify aircraft Small intensely fluorescent cell Source Input Format, a MPEG-1 video format Standard Interchange Format, a format for geographic data Stress intensity factor, used in fracture mechanics to predict the stress state
Sport Supreme Indoor Football, a defunct American sport league
Clubs SÍF Sandavágur, a Faroese football club Sandvikens IF, a Swedish football club Silkeborg IF, a Danish football club Stattena IF, a Swedish football club in Helsingborg Stavanger IF, a Norgwegian football and handball club SIF Stadion, their home venue Stocksunds IF, a Swedish sport club in Stocksund Strømsgodset IF, a Norwegian sport club Strømsgodset Toppfotball, their professional football team
Transport AirSial, a Pakistani airline Rockingham County NC Shiloh Airport, in North Carolina Simara Airport, in Madhesh Province, Nepal TF-SIF (Dauphin 2), an aircraft operated by the Icelandic Coast Guard from 1985 until 2007 TF-SIF (Dash 8), an aircraft operated by the Icelandic Coast Guard since 2009
Other organizations Central European Institute of Philosophy () Science of Identity Foundation, an American religious organization Seychelles Islands Foundation Shropshire Islamic Foundation Singapore International Foundation, a Singaporean charity Swedish Union of Clerical and Technical Employees in Industry ()
Other uses 4484 Sif, a main-belt asteroid Siamou language Sif Mons, a shield volcano on Venus Specialized investment fund Love Live! School Idol Festival, a mobile game
See also Short Interframe Space (SIFS), the small time interval between the data frame and its acknowledgment