The lap record fell several times in qualifying before Martin went fastest, clocking one minute and 56.160 seconds to claim his second pole with Aprilia.
"I put everything I had on the track, I didn't expect to do this great lap time, honestly," Martin said.
"But yesterday we confirmed that the feeling is improving, today we did another small step. Last year I didn't race (much) and I was struggling a lot to manage the speed, of how fast are we going.
"But to be in pole position is always super special and for sure here in Silverstone is something else. So let's try to work well and try to fight for that victory."
Trackhouse riders Raul Fernandez of Spain and Japan's Ai Ogura, who is second in the championship, complete the front row.
"I'm happy, but always we are missing this pole position for small details," Fernandez said.
"But, anyway, I think we are working well. Now we have to think which is the right tyre for the sprint race because still we are not 100% clear. But I think we are doing a good job, step-by-step I feel much more comfortable with the bike."
VR46 Racing's Fabio Di Giannantonio was fourth quickest while Aprilia's Marco Bezzecchi marked his return from shoulder surgery to go fifth-fastest.
Reigning champion Marc Marquez could only manage sixth and the Ducati rider will start from the second row after he edged his brother Alex.
Only 24 points separate the top five of Martin, Ogura, Marquez, Bezzecchi and Di Giannantonio heading into Saturday's sprint.