Tom Brady has the most career games by a quarterback in championships, with 14 games.

most conference championship appearances by qb
BradyYoungMontanaStaubachElwayBradshawRodgersRoethlisbergerManningMcNabbFavreKellyStablerMahomesDetmerAikmanReichKosarKubiakWhiteMorrallMorton14777665555555444444444
NAMEROUNDGPCMPATTPCTYDSAVGYDS/GTDTD%INTINT%SCKSCKYRATE
Tom BradyTom BradyNFC Championship1432452461.83,6747.0262.4214.0173.22111982.7
Steve YoungSteve YoungNFC Championship79014960.41,0367.0148.042.742.7115079.2
Joe MontanaJoe MontanaAFC Championship713722361.41,7317.8247.3135.873.1137992.0
Roger StaubachRoger StaubachNFC Championship76913351.98016.0114.475.386.01710662.9
John ElwayJohn ElwayAFC Championship69818652.71,4147.6235.7105.442.21311186.6
Terry BradshawTerry BradshawAFC Championship67113652.29857.2164.275.1107.474262.3
Aaron RodgersAaron RodgersNFC Championship512719664.81,3817.0276.294.684.1129683.7
Ben RoethlisbergerBen RoethlisbergerAFC Championship59215260.51,2037.9240.663.963.995282.2
Peyton ManningPeyton ManningAFC Championship512520860.11,5397.4307.894.352.4129687.4
Donovan McNabbDonovan McNabbNFC Championship59917456.91,0696.1213.863.463.4139572.2
Brett FavreBrett FavreNFC Championship510317658.51,3677.8273.495.174.064483.7
Jim KellyJim KellyAFC Championship57812960.59177.1183.443.186.253666.6
Ken StablerKen StablerAFC Championship57915252.09496.2189.874.674.666867.6
Patrick MahomesPatrick MahomesAFC Championship49414365.71,1898.3297.3128.421.41187113.7
Koy DetmerKoy DetmerNFC Championship481553.3916.122.800.016.71844.0
Troy AikmanTroy AikmanNFC Championship48913864.51,1348.2283.585.832.21067100.3
Frank ReichFrank ReichAFC Championship40000.00000
Bernie KosarBernie KosarNFC Championship46812654.09087.2227.086.364.884378.4
Gary KubiakGary KubiakAFC Championship4111291.713611.334.000.000.0110113.9
Danny WhiteDanny WhiteNFC Championship4377052.94135.9103.322.922.954968.3
Earl MorrallEarl MorrallAFC Championship471163.6514.612.819.119.10066.9
Craig MortonCraig MortonAFC Championship4174240.53257.781.337.112.431881.9
Jimmy GaroppoloJimmy GaroppoloNFC Championship3223857.93098.1103.025.312.61890.8
Joe FlaccoJoe FlaccoAFC Championship35610254.96876.7229.054.943.984575.9
Drew BreesDrew BreesNFC Championship37012058.38006.7266.775.821.765091.0