Marlieux (French pronunciation: [maʁljø] ; Arpitan: Marelyô) is a commune in the Ain department in eastern France. Marlieux—Châtillon station has rail connections to Bourg-en-Bresse and Lyon.
The river Chalaronne forms part of the commune's western border.
Marlieux has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Marlieux is 12.2 °C (54.0 °F). The average annual rainfall is 909.1 mm (35.79 in) with October as the wettest month. The temperatures are highest on average in July, at around 21.3 °C (70.3 °F), and lowest in January, at around 3.4 °C (38.1 °F). The highest temperature ever recorded in Marlieux was 41.3 °C (106.3 °F) on 13 August 2003; the coldest temperature ever recorded was −23.0 °C (−9.4 °F) on 6 January 1971.
