Willis is a city in Montgomery County, Texas, United States, located eight miles north of Conroe in north central Montgomery County. The city began to develop in 1870 after what is now the Union Pacific Railroad built track through the area. As a part of the Piney Woods, the Willis economy has historically been driven by lumber, agriculture, and the manufacture of lumber and agriculture equipment. From the late nineteenth to early twentieth century, it produced tobacco as a commodity crop. Competition from Cuba reduced its contribution to the economy.
As of 2020, the population of Willis was estimated to be 6,431. In 2008, after Willis's population passed 5,000, the city established a home rule city charter.
Willis is located at (30.422640, –95.478829).
According to the United States Census Bureau, the city has a total area of , all of it land.
Before the founding of Willis, most residents in the area lived in a settlement known as Danville,