He served in the United States Army Air Force during World War II and was a graduate of Knox College.

Defebaugh married Lois on October 17, 1953; she died in the fall of 2013.

The chairman of the Oakland County Republican Party from 1968 to 1970, Defebaugh was elected to the House in 1970.

During his tenure in the House, he was Republican whip and assistant floor leader.

With his wife, he also traveled to 21 countries in Europe, Asia, Australia, and New Zealand.