Gonneville-le-Theil () is a commune in the department of Manche, northwestern France. The municipality was established on 1 January 2016 by merger of the former communes of Gonneville and Le Theil.
Gonneville-le-Theil has an oceanic climate (Köppen climate classification Cfb). The average annual temperature in Gonneville-le-Theil is . The average annual rainfall is with December as the wettest month. The temperatures are highest on average in August, at around , and lowest in February, at around . The highest temperature ever recorded in Gonneville-le-Theil was on 19 July 2006; the coldest temperature ever recorded was on 17 January 1985.