In the Swedish version, the scene showing Jennings being decapitated has been cut down with 11 seconds
In the 2017 Netflix release, the End title card (after Damien's smile) featuring the Revelation 13:18 quote about the 'Number of the Beast' is completely removed from the film.
SPOILER: Near the end, when Robert has Damien in the car in his driveway, scenes of the Rottweiler and Mrs. Baylock attacking one more time were filmed but ultimately cut. Originally, Robert killed her by running her over with the car twice. Director Richard Donner says he cut it because the scene "went on forever." However, the idea was later loosely re-used for the 2006 remake, The Omen (2006).
In the original ending of the film, there were three coffins at the funeral. This was changed at the last minute and the crew returned to the cemetary to film the scene with just two coffins.