Dawn E. Pettengill (born July 2, 1955) is an American retired politician from Iowa.

On April 30, 2007, she switched to the Republican Party, having previously served in the House as a Democrat.

She also serves as the vice chair of the Administrative Rules Review Committee and was co-chair of the Public Retirement Systems Committee and as a member of the Investment Board of the Iowa Public Employees' Retirement System.

She subsequently won re-election in 2006, defeating Republican opponent Connie Jacobsen.

Pettengill was unopposed in 2010, and defeated Democrat Sandra Cronbaugh in 2012, Steve Beck in 2014 and Paula Denison in 2016.