Dunlop posted the fastest lap overall in qualifying to claim Superbike pole on his MD Racing BMW.
He lapped in 1m 23.571s for the top spot, with Magherafelt man Paul Jordan second on the combined times in the Open class on his Jackson Racing Ducati Panigale V2 Supersport machine.
Jordan, who took pole in the Supersport class, lapped in 1m 23.796s, while Skerries rider Michael Sweeney slotted into third on his MJR BMW (1m 24.669s).
Dunlop broke his 12 year-old lap record in 2025 on his way to victory in the feature race with a speed of 91.773mph (1m 22.377s), which remains the fastest lap at the event.
Manxman Marcus Simpson (Honda) was next in a time of 1m 25.453s ahead of Darryl Tweed (JLR Ability Energy Ltd Honda) and Sean Brolly in sixth, who impressed on his Ducati Panigale V2 Supersport machine.
Dunlop earlier claimed pole in the Moto3/125GP/Supersport 300 class on the Burrows Engineering/RK Racing Honda at the Co Tyrone course.
Have a look at some of the best pictures so far:
1. Cookstown 100
Michael Dunlop was out on the Burrows Racing Moto3 at the Bear Competitions Cookstown 100 Photo: Rod Neill/Pacemaker Press
2. Cookstown 100
Crowds enjoy the sunshine at the Bear Competitions Cookstown 100 Photo: Rod Neill/Pacemaker Press
3. Cookstown 100
Michael Dunlop is amongst the riders at the Bear Competitions Cookstown 100 Photo: Rod Neill/Pacemaker Press
4. Cookstown 100
Paul Jordan (JR Racing Ducati) was fastest in Supersport qualifying at the Bear Competitions Cookstown 100 Photo: Rod Neill/Pacemaker Press