Forrest Smith was born February 14, 1886 near Hardin in Ray County, Missouri. After receiving his secondary education at Woodson Institute in Richmond, Missouri, Smith attended Westminster College (Missouri).

On October 12, 1915 he married Mildred Williams and they were the parents of two daughters, Forrestine and Mary Josephine.

Forrest Smith began his lifelong political career in 1910 when he became deputy assessor for Ray County, Missouri. In 1914 he was elected county clerk for Ray County, a post he held for the next eight years.

From 1925 to 1932 Smith served on the Missouri state tax commission, a post that laid the groundwork for a long career in statewide elected office.

In 1932 Forrest Smith was elected Missouri state auditor, a post he would hold for the next sixteen years until being elected governor in 1948.

According to the August 16, 1948 issue of Time magazine, Smith "helped get himself re-elected by reminding voters he was the man who mailed out the old-age pension checks."

In his mid-60s with a lifetime of public service, Governor Smith retired from public life following completion of his term in January 1953. Governor Smith died March 8, 1962 in Gulfport, Mississippi.

He is buried in Sunny Slope Cemetery, Richmond, Missouri