Bernard "Barney" Rubble is a blond-haired caveman married to Betty Rubble and best friend of neighbors Fred and Wilma Flintstone. Though no age is ever given, all four of them appear to be somewhere in their late twenties in the original television series, adults but still a little unseasoned by life and occasionally prone to daydreams, get-rich-quick schemes, and youthful misadventures.

Easygoing and with a forgiving nature, Barney prefers to coast through life without worry, often letting other people take advantage of him just because it's easier than getting upset about it. As a consequence, his best friend Fred unconsciously takes advantage of him constantly without either of them realizing it. His one sore point is when someone accuses him of disloyalty to his friends, and when Barney does lose his temper, watch out!

Barney often has trouble expressing his thoughts yet has a natural hands-on genius, such as building a flying machine in his backyard for fun or a money printing press as a harmless practical joke but unable to explain how any of it works. Similarly, he shows his love for wife Betty not with compliments but with a spontaneous gift of flowers and open displays of affection. Both Barney and Fred endure teasing from their wives whenever they become disastrously cocky or recklessly naive (a fairly common occurence in a domestic sitcom such as The Flintstones).

In the original series continuity, Barney and Fred met Wilma and Betty while working at a ritzy motel during one of their first summers after graduating from high school. His courtship with Betty was gentle and sweet, and despite the occasional quarrel, the two of them have remained fiercely protective of each other ever since. In later continuities, the four of them have known each other since children. The Flintstones series have never really attempted to follow a single continuity, so both origins are probably true.

During the original television series run, Barney and Betty discovered they were unable to bear children, and in a unique turn of events for 1960s television, chose to adopt a son, in this case the world's strongest toddler Bamm Bamm. In sequel television series, Barney enters middle age with nary a gray hair as son Bamm Bamm Rubble marries Pebbles Flintstone and, in one continuity, may have become a grandfather.

Like all the "cave people" of The Flintstones series, Barney easily performs feats of strength that are superhuman by modern standards, including lifting stone slabs twice his size overhead, and would appear to have a low level of invulnerability compared to a modern human being. (This greater strength and toughness has been vaguely alluded to the few times that the Flintstones and Rubbles have travelled into their future to the modern day or even past that to the retrofuturistic days of the Jetsons).