Björg Siv Juhlin Friðleifsdóttir (born 10 August 1962) is an Icelandic politician.
She was a member of the Althing (Iceland's parliament) for the Progressive Party for the Rekyanes constituency from 1995 to 2003 and has represented the Southwest Iceland constituency since 2003. She has been Chairman of the Progressive Party parliamentary group since 2007, and was Minister of Health and Social Security from 2006 to 2007, Minister for the Environment and Minister for Nordic Cooperation from 1999 to 2004.
One of her notable policies was to make it illegal for strip clubs (and strippers) to operate in Iceland. This was made possible by a mostly-female parliament trying to develop female-friendly policies. Iceland's sex industry has been shut down by feminist politicians on July 30, 2010. Under Siv's law, Iceland has become the first European country to ban strip clubs.