Alexander Gilmer (September 7, 1829 – July 30, 1906) was a sawmiller that became one of the United States' most successful individual timberland owners in his era.
Nicknamed "Sandy", he was born in County Armagh, Ireland, the son of George and Jane Gilmer.
He immigrated to Georgia at the age of seventeen where he constructed shipmasts for the French government with his brother John.
Together, they built a steamboat to work the Chattahoochee, but suffered a major setback when it sank, leaving Gilmer almost penniless.
In his last days, Gilmer traveled to San Antonio for health reasons before making his last business trip to New York City where he died in 1906.