She was born in 1966 in Gaziantep. She completed her primary, secondary and high school education in Gaziantep, and her higher education at Istanbul Technical University, Department of Chemistry and Metallurgy. She worked as an Operation Engineer and Operation Manager for 18 years at SANKO Holding, where she started her business life. In 2001, she became the Gaziantep Provincial Founding Member of the Justice and Development Party. She was elected as the first woman Member of Parliament from Gaziantep in the 2002 general parliamentary elections. She served as Gaziantep Member of Parliament for the 22nd, 23rd and 24th terms in the Parliament. During her tenure at the Grand National Assembly of Turkey, she served as a member of the Industry, Trade and Energy Commission, a member of the Turkish-EU Joint Parliamentary Commission, and the Chairperson of the Research Commission on Violence Against Women and Children. She undertook the Vice President in Charge of the Organization for one term and the Vice President in charge of Political Affairs for a period under the Presidency of the Women's Branch of the AK Party Headquarters. She served as the President of the AK Party Headquarters Women's Branch between 2007-2011. She was appointed as the Founding Minister of the Ministry of Family and Social Policies in the 61st government, established after the 2011 general parliamentary election. Thus, she received the title of the first woman Minister of the Southeastern Anatolia Region. The disabled People's Foundation of Turkey selected Minister Fatma Şahin as the Woman of the Year for her work on disabled people. In the local elections held on 30 March 2014, she was elected as one of the first woman metropolitan mayors of Turkey and became the Mayor of Gaziantep Metropolitan Municipality. She was elected as the President of the Union of Municipalities of Turkey on May 8, 2018. She served as the President of the Asian Mayors Forum 2016 - 2019, the 2016 Vice President of United Cities and Local Governments, and the Head of the Middle East and West Asia Department of the United Cities and Local Governments.
Şahin is married and has two children. She still continues her duties as the President of the Union of Municipalities of Turkey and Gaziantep Metropolitan Municipality.