Fabian Giefer (born 17 May 1990) is a German professional footballer who plays as a goalkeeper for FC Augsburg in the Bundesliga.

Giefer began his football career at 1. FC Oberahr as his first youth club. He then move to TuRa Lommersdorf before moving to Bayer Leverkusen. Giefer was promoted to the Bayer Leverkusen first team ahead of the 2009–10 season. On 4 June 2012, it was announced that Giefer would join Fortuna Dusseldorf with a two-year contract until 30 June 2014. It was announced on 6 December 2013 that Giefer would join Schalke 04 next season. On 19 January 2017, Bristol City announced the loan signing of Giefer until the end of the season. On 8 June 2017, after leaving Schalke 04, Giefer joined FC Augsburg, signing a four-year contract, keeping him until 2021.

After representing the Germany youth team for five years, Giefer was called up by Germany U20 in November 2010. Two years on, Giefer was called up by Germany U21, but withdrew and was replaced by Kevin Trapp.