Gymnast Louis Smith's win in Saturday's tenth series climax was the second most-watched ever behind 2010's finale.
BBC One's 90-minute broadcast, airing between 6.30pm and 8pm, averaged 12.35m and a 49.1% share - eclipsing the audience for last year's final.
The penultimate episode of Merlin followed with an impressive 7.25m (30.2%), before Strictly returned at 9pm for its results show with 12.11m (46.4%). BBC News logged 8.44m (36.6%) and Match of the Day capped an excellent night for the channel with 3.97m (24.9%).
Earlier in the evening, Pointless Celebrities entertained 5.96m (29.2%), while ITV1 could only muster 1.61m (6.3%) for The Nation's Favourite Christmas Song from 6.30pm (+1: 143,000).
A Top of the Pops 2 festive edition enthralled 1.99m (8%) on BBC Two from 8pm, while 5's screening of A Christmas Carol interested 1.49m (6%) as well as 154k on +1. Channel 4's film Four Christmases fetched 1.48m (6%) from 9pm (+1: 496k).
Overall, BBC One dominated primetime with a huge 40% share, way ahead of ITV1's 8.7% (+1: 0.8%), BBC Two's 5.7%, Channel 5's 5.1% (+1: 0.5%) and Channel 4's 4% (+1: 0.8%)
BARB ratings data supplied by Attentional