Lenawee Christian School began in 1977 as Trenton Hills Christian School, under the sponsorship of Trenton Hills United Brethren Church of Adrian. Thanks to the generous financial support of Mr. and Mrs. Orville Merillat, a small school building was built on the church property. The school began with two teachers, an administrator, and 17 students, kindergarten through grade three. Each year, a new grade was added, and by 1984 classes extended through the eighth grade. A Christian high school began in the fall of 1985, bringing the school’s total enrollment to 450 students.

In 1985, the Merillats funded the construction of the present facility—including Lenawee Christian School and the Christian Family Centre—on the west side of Adrian. They also established the Christian Family Foundation (now Lenawee Christian Ministries) for the purpose of “fostering Christian and traditional family values in a Christ-centered atmosphere.” Today, LCS and The Centre continue the Merillat family's commitment to high quality programs that glorify God through nurturing spiritual, social, and physical wellness in a safe environment.