Both of Josh Murphy's goals had an element of class to them, the attacker first bending a shot into the far corner before rounding the goalkeeper for his second.
Bolton, who had finished the regular season in third, had no answer and barely laid a glove on their opponents as Oxford ended a 25-year wait for another appearance in the second tier.
Wembley-born Murphy sparkles at national stadium
Although Oxford showed the most intent during the early stages, Bolton had the first real shot of note as Josh Sheehan sent a long-range strike wide of the target.
In response during a quiet opening 25 minutes, Ruben Rodrigues fired similarly wide for Oxford, before the game finally livened up shortly after the half-hour mark as Oxford took the lead.
Murphy was provided with far too much space to get down the flank and cut inside, the winger able to find the far corner of the net via the aid of a deflection from the corner of the area.
Three minutes before the break, Murphy got his second to double Oxford's advantage with another brilliantly-taken goal, Rodrigues releasing his teammate who was able to take the ball around goalkeeper Nathan Baxter and slot into an empty net from an acute angle.
Bolton fail to find response in second half
While Bolton showed a bit more intent immediately after the break, Oxford and Murphy almost had their third shortly before the hour mark with Murphy having manoeuvred himself past a defender, but his eventual shot was dragged wide of goal.
Moments after Oxford were dealt a blow with the injury to key man Cameron Brannagan, Murphy was presented with another chance, running half the length of the pitch before finding the angle too tight to find a way past Baxter.
Such was the desperation of Bolton boss Ian Evatt that he made a triple-change, including withdrawing 16-goal striker Dion Charles, yet it was Oxford who continued to push.
After goalkeeper Baxter had committed a foul on the side of the area, earning himself a caution, Joe Bennett's free kick needed to be punched behind by the Bolton stopper.
Another chance then went the way of Murphy, who headed wide at the back post, before up the other end, Bolton substitute Cameron Jerome sent a header of his own off target.
With nine minutes added on, Oxford would have been wary of a Bolton revival, but their defensive line, as it was all afternoon, was superb in nullifying any genuine threat as Des Buckingham's side were left to celebrate Oxford's greatest victory in a quarter of a decade.