Robert Augustus Barnes (November 29, 1808 – April 2, 1892) was a self-made businessman in the St. Louis area.

Barnes was born in Washington, D.C., but moved to Louisville, Kentucky at the age of thirteen after the death of his father.

Soon afterwards, he began his own grocery business and held partnerships with prominent St. Louis businessmen.

[1] Robert Barnes was a philanthropist during his lifetime, but his greatest contribution came after this death.

Barnes wanted to build "a modern general hospital for sick and injured persons, without distinction of creed..."[2][4] His generosity, together with funds raised from the Jewish community in St. Louis, gave rise to what is now the Barnes-Jewish Hospital in St. Louis, Missouri.