The 71-year-old actor will marry his girlfriend, Sibylle Szaggars, a German artist who is 19 years younger than him, reports FemaleFirst.
Redford, who was once married to Lola Van Wagenen, announced, "We are engaged and very happy with that. Sibylle is my fiancee and that says everything, doesn’t it?"
Redford and Szaggars have been dating since 1996.
The actor has four children from his first marriage, Shauna, 48, Jamie, 46, Amy, 38, and Scott, who died in 1959.