Marlin is located just southeast of
Waco and northeast of
Temple where Hwys 6, 7 and 86 meet in
Falls County, where it is county seat.
By the 1990s there was an auction barn, and independent cattle trucking companies. The growing number of senior citizens has given rise to federally funded housing apartments, a civic center, two nursing homes, transportation vans, and a new office building for Texas Human Resources. The old Buie-Allen Hospital is a halfway house for girls. In September 1989 the Texas Department of Corrections opened the 1,000-bed William Pettus Hobby Unit.
In 1990 the population of Marlin was 6,386.