The country music legend - who has been married to husband Carl Dean for 55 years - thinks the talk show host is "precious" and they've always got along well.
"Well, I have a crush on Jimmy Fallon, but I'm big now, I can't excuse myself on that!" she admitted in an interview with W magazine. "I think he is precious. He's so funny. We get along so good."
Dolly admitted Jimmy isn't the only talk show host she's felt a connection with as she had a "nice relationship" with David Letterman and the late Johnny Carson.
"Sometimes you never know who you're gonna connect with," she added. "I've always had good luck with late-night guys, you know? I always had a nice relationship with David Letterman and with Johnny Carson."
"I guess there's something about late-night people that kinda hits my fancy and I hit theirs somehow. I guess it's 'cause you feel like you can be more free late at night. You don't have to worry about what you say."
Dolly has always "loved boys" and she admitted she had a "big crush" on the late Johnny Cash in the early days of her career because he was "so, so sexy" - although she later discovered he was coming through drug addiction at the time.
She recalled, "I had a lot of boys in my life. I love boys. I still do. In the early days, I had a big crush on Johnny Cash. He was young and skinny, and he just had that magnetism. The way he moved around - you know, so sexy."
"I found out later he was just having withdrawals from drugs, but it still touched me. He was so, so sexy."