Olyphant's TV credits include FX's "Damages" and HBO's "Deadwood."
The new as-yet-untitled pilot is set to start shooting late next month. In it, Olyphant will play Raylan Givens, a U.S. marshal who returns to his hometown in Kentucky, The Hollywood Reporter said.
"He has a certain jaggedness, but he also loves his job," creator-executive producer Graham Yost told the entertainment industry trade newspaper. "He is like an anachronism: He wears a hat, cowboy boots and a holster on his hip. It's a little bit like he was born 100 years too late."
Yost predicted Olyphant will do as well at portraying a Leonard character as did his predecessors George Clooney in "Out of Sight" and John Travolta in "Get Shorty."
"(The characters) are very good at what they do; they have confidence but without swagger and a great sense of humor in a dry way," Yost said.