|Family|| Lorraine Baines-McFly (mother)|
|Portrayed By||Marc McClure|
Dave was quite laid back, and liked to laugh at his own jokes. He had a close bond with his father in nearly all timelines, and was probably the McFly sibling who got along with George the best. Dave liked to watch The Honeymooners with his father and had no real interest in sports.
Back To The Future
In the first timeline, (October 25, 1985), Dave was working at Burger King where he may have been working for some time. Dave had to catch the bus to work (although in the novelization, he did own a tatty old car, much to the envy of Marty), suggesting that he could not afford a car and/or the insurance for one on his wages. The job suggested that Dave may not have done that well at school, or he may have been bullied like his father before him.
After Marty returned to 1985 from 1955, he found that his actions in the past had altered the lives of his family. Presumably due to having more confident parents, Dave had done much better in his life in this timeline and now worked in an office, for which he had to wear a suit. It would appear though that even in this timeline, Dave did not have a car, as he seems annoyed when Marty thought that the family car was wrecked (which it was in the original timeline). Presumably, he had moved out of his boyhood home, and was only stopping by for breakfast.
In the 1985A timeline, Biff had become rich (due to a sports almanac given to him by his 2015 self in 1955) and was the McFly siblings' stepfather after murdering George and marrying Lorraine. Biff said that if Lorraine left him, he would have "Dave's probation revoked" — indicating that Dave had been in trouble with the police, which Biff owned.
After Marty successfully managed to set history right by taking the almanac off Biff in 1955, Dave reverted to the office worker that he was before, and was seen by Marty briefly as the family headed out to lunch.