Factual error: The narrator is telling ('According to a report in the Saint James Chronic...') that Lady Lyndons father, Charles Lyndon (played by Frank Middlemass), died at Spa, in the Kingdom of Belgium. There's no year mentioned in this scene, but at the end of the movie (a few years later), when Lady Lyndon signs a cheque for Barry, we can see on this cheque the year 1789. The Kingdom of Belgium did not yet exist in 1789: Belgium became a Kingdom in 1831 (21st of July to be exact).

Factual error: While Stanley Kubrick boasted about the authenticity of the candlelit interiors, he must have missed the little drawing of a steam train on a period map - 40 years before trains were invented.

Continuity: In the scene where Lord Bullingdon and Barry jr. are left behind by the chaplain while at their lessons, Lord B. is copying a text. The various shots showing his writing seem to be in the wrong order: in some shots there is a line of writing less than in the previous shot.

Factual error: In the scene where Barry Lyndon is talking to his mother privately, while standing on the bridge overlooking the water, Barry's mother refers to Barry's son Brian as being "at the mercy of his stepbrother", meaning Lord Bullingdon. They have the same mother. Lord Bullingdon and Brian would be half brothers, not step brothers.

Continuity: Barry is introduced to Gustavas Adolphis, the 13th Earl of Wendover, by Lord Hallam, to help him obtain a title. In the receiving line to meet Your Majesty, another man is introduced as Lord Neville, yet later when Barry is eating in a restaurant and runs into the 13th Earl of Wendover, he calls him Lord Neville. It seems his name should be either Lord Wendover, as he was called previously, or Lord Adolphis, as we learned that his real name was from Lord Hallam.

Continuity: In the scene when Barry interrupts the meeting of Nora and Captain Quin, the direction of the light source changes several times, indicating repeat takes.

Continuity: Barry Lyndon bloodies Mr. Toole's face in a boxing match. The blood disappears in the next shot.

Factual error: In the scene where Barry is in the rowboat on the lake, there is a yellow Labrador retriever in the boat. Yellow Labs were not bred until around 1900.