Le Poizat-Lalleyriat (French pronunciation: [lə pwa'za lalɛ'ʁja]) is a commune in the Ain department of eastern France.

The municipality was established on 1 January 2016 and consists of the former communes of Lalleyriat and Le Poizat.

The average annual temperature in Le Poizat-Lalleyriat is 8.3 °C (46.9 °F).

The average annual rainfall is 1,752.5 mm (69.00 in) with December as the wettest month.

The temperatures are highest on average in July, at around 17.6 °C (63.7 °F), and lowest in January, at around 0.0 °C (32.0 °F).