Here are some of the dialogue quotes that the actors say in the movie:
- Strickland: "You got a real attitude problem, McFly. You're a slacker. You remind me of you father when he went here. He was a slacker, too."
- Marty: "Can I go now, Mr. Strickland?"
- Strickland: "I noticed your band is on the roster for the dance auditions after school today. Why even bother, McFly? You don't have a chance. You're too much like your old man. No McFly ever amounted to anything in the history of Hill Valley!"
- Marty: "Yeah? Well, history is gonna change."
- — 
Lorraine: I don't like her, Marty. Any girl who just calls up a boy is just asking for trouble.
Linda: Oh, Mom, there's nothing wrong with calling a boy.
Lorraine: I think it's terrible! Girls chasing boys. When I was your age I never chased a boy or called a boy or sat in a parked car with a boy. 
Linda: Then how am I supposed to ever meet anybody?
Lorraine: Well, it will just happen, like the way I met your father.
Linda: That was so stupid! Grandpa hit him with the car.
- Marty: "Wait a minute. Wait a minute Doc, are you telling me you built a time machine... out of a DeLorean?"
- Doc: "The way I see it, if you're going to build a time machine into a car, why not do it with some style? Besides, the stainless steel construction made the flux disperal... Watch Out!!"
Marty: Sorry about your barn. (Old Man Peabody tries to shoot him)
Sherman Peabody: It's already mutated into human form, shoot it!
Old Man Peabody: Take that, you mutated son of a bitch!
Doc Brown: Tell me, Future Boy, who's President of the United States in 1985?
Marty: Ronald Reagan.
Doc Brown: Ronald Reagan? The actor? Then who's vice-president, Jerry Lewis? I suppose Jane Wyman is the First Lady!
Marty: Whoa, wait, Doc!
Doc Brown: And Jack Benny is Secretary of the Treasury! 
- Doc: "Now remember, according to my theory you interfered with with your parents' first meeting. They don't meet, they don't fall in love, they won't get married and they wont have kids. That's why your older brother's disappeared from that photograph. Your sister will follow and unless you repair the damages, you will be next."
- Marty: "Oh, this is heavy."
- Doc: "Weight has nothing to do with it!"
- — At Hill Valley High School
- Marty: "This is heavy, Doc."
- Doc: "There's that word again: "heavy." Why are things so heavy in the future? Is there a problem with the Earth's gravitational pull?"
- — 
- George: "Okay, but I don't know what to say."
- Marty: "Just say anything, George. Say whatever's natural, the first thing that comes to your mind."
- George: "Nothing's coming to my mind."
- Marty: "Jesus, George, it's a wonder I was ever born."
- — 
Marty: What about all that talk about screwing up future events? The space-time continuum?
Doc Brown: Well, I figured, what the hell!
- Marty: "Doc, we're not going to have enough road to get up to 88."
- Doc: "Roads? Where we're going, we don't need roads."
- — Doc and Marty in the DeLorean
- ↑ The dialogue foreshadows what will happen after Marty goes back in time, but the line was added after Fox came on board. In the 1984 draft, Marty wasn't going to the audition at all because he was getting detention. The scene closed with Strickland saying "Too bad, McFly. I guess this isn't your day."
- ↑ Prior to filming, Lorraine added that "Boys won't respect you Linda. They'll think you're cheap."
- ↑ Reportedly, President Reagan enjoyed the line so much in a private showing of the film that he had it replayed. In the 1984 script, Doc's response was simply "That's a good one! The kid's a riot! A regular riot!".
- ↑ These lines were added after filming began with Fox
- ↑ This exchange had been written as part of the 1980 draft, and was only slightly altered in rewrites