Shields competed at the 2012 FINA World Swimming Championships (25m) in Istanbul, Turkey. He finished second in the 100 meter butterfly (49.54) and third in the 50 meter butterfly (22.46). Shields's time in the 50 meter butterfly was a new American Record. Additionally, the relay team of Matt Grevers, Kevin Cordes, Shields, and Ryan Lochte swam to a gold medal finish in the 4 × 100 meter medley relay.