Peter Hickman remains the fastest rider in history around the 37.73-mile Mountain Course, setting the outright lap record at 135.452mph (16m 42.778s) on his way to a dramatic last lap victory over Dean Harrison in the Senior TT in 2018.
Bradford rider Harrison, riding the new-look DAO Kawasaki machines this year, holds the lap record for the Superbike TT at 134.432mph (16m 50.384s), also set in 2018.
Hickman also set the current benchmark in the Superstock TT in 2018, lapping at a staggering 134.403mph (16m 50.501s) on the production-based Smiths BMW S1000RR.
Manx Grand Prix: Michael Dunlop gears up for Classic Superbike victory bid on new Team Classic Suzuki GSX-R750
Kofi Balmer 'feels amazing' after making dream move to Crystal Palace
Jeremy McWilliams notches Bishopscourt double at Classic Bike Festival Ireland on Michael Dunlop's Team Classic Suzuki
In Pictures: Team NI's Commonwealth Games medal winners
Blackpool reject bid for Shayne Lavery amid Millwall speculation
The Ballymoney man lapped at 129.197mph (17m 31.328s) in the Supersport race in 2018 and claimed the Lightweight (Supertwin) lap record during the same year on the Italian Paton machine at 122.750mph (18m 26.543s).
Every lap record fell in 2018 during two weeks of almost unbroken fine weather on the Isle of Man, which was in stark contrast to some of the worst weather the following year, when the TT was last held in 2019.
Ben and Tom Birchall crept ever closer to a 120mph Sidecar lap record following a speed of 119.250mph (18m 59.018s).
Hickman remains the fastest Newcomer with a lap of 129.104mph (17m 32.078s) in 2014.
Northern Ireland’s Glenn Irwin is among the newcomers this year, when the six-time North West 200 Superbike winner will line up on the Honda Racing UK Fireblade alongside team-mate John McGuinness. The Carrickfergus man set the quickest ever qualifying lap by a newcomer as practice commenced on Sunday at 122.616mph on his Superbike.
Jenny Timouth is the fastest ever female around the TT course, lapping at 119.945mph (18m 52.42s) in 2010.