Lamar Jackson has the best completion percentage with 40+ passing attempts this season, at 86.0 percent.

highest completion percentage in a game minimum 40 attempts
Interpreted as:
highest completion percentage by a player in a game minimum 40 passing attempts this regular season
2021Jackson2021Tagovailoa2021Prescott2021Bridgewater2021Cousins2021Brady2021Allen2021Ryan2021Mills2021Roethlisberger2021Herbert2021Jones2021Hurts2021Goff2021Stafford2021Tannehill2021Mahomes2021Brissett2021Jones2021Garoppolo2021Heinicke2021Carr2021Lawrence86.074.771.671.471.168.868.868.267.467.467.267.066.766.765.964.063.462.962.662.562.160.657.6
NAMESEASONTMGPPCTATTCMPYDSAVGYDS/GTDTD%INTINT%SCKSCKYRATE
Lamar JacksonLamar Jackson2021BALBAL186.0433744210.3442.049.300.025140.5
Tua TagovailoaTua Tagovailoa2021MIAMIA274.787656207.1310.066.933.4110102.7
Dak PrescottDak Prescott2021DALDAL271.6109788487.8424.065.521.8112104.8
Teddy BridgewaterTeddy Bridgewater2021DENDEN171.449353346.8334.036.136.152584.9
Kirk CousinsKirk Cousins2021MINMIN271.197697247.5362.055.200.0326109.6
Tom BradyTom Brady2021TBTB568.82311591,7887.7357.6125.231.3644103.6
Josh AllenJosh Allen2021BUFBUF368.8141979817.0327.085.710.7634104.4
Matt RyanMatt Ryan2021ATLATL468.21731181,2617.3315.3105.842.332698.9
Davis MillsDavis Mills2021HOUHOU167.443292435.7243.000.024.721462.5
Ben RoethlisbergerBen Roethlisberger2021PITPIT467.41781201,0746.0268.542.242.293981.5
Justin HerbertJustin Herbert2021LACLAC367.2131881,0808.2360.064.632.364598.1
Mac JonesMac Jones2021NENE267.091615456.0272.533.344.464475.6
Jalen HurtsJalen Hurts2021PHIPHI166.748323878.1387.024.200.0329105.1
Jared GoffJared Goff2021DETDET266.799665405.5270.033.022.043482.0
Matthew StaffordMatthew Stafford2021LARLAR265.982546147.5307.056.111.217103.4
Ryan TannehillRyan Tannehill2021TENTEN264.089576457.2322.511.100.0107289.4
Patrick MahomesPatrick Mahomes2021KCKC363.4145929296.4309.774.864.171680.5
Jacoby BrissettJacoby Brissett2021MIAMIA262.989563844.3192.000.011.164267.8
Daniel JonesDaniel Jones2021NYGNYG262.691576447.1322.022.244.444172.8
Jimmy GaroppoloJimmy Garoppolo2021SFSF162.540252576.4257.025.012.542687.2
Taylor HeinickeTaylor Heinicke2021WASWAS262.187545846.7292.022.333.432275.1
Derek CarrDerek Carr2021LVLV260.699608218.3410.544.022.065592.2
Trevor LawrenceTrevor Lawrence2021JAXJAX257.692536517.1325.544.333.332080.5
Sam DarnoldSam Darnold2021CARCAR141.541172075.0207.012.412.441955.6
StatMuse has game-level data for completion percentage and passing attempts going back to the 1950 season.