McLaren's Lewis Hamilton and Ferrari's Fernando Alonso, favourite of his home Spanish crowd, will line up together on the second row on Sunday.
Webber has yet to win a race this season but was triumphant last year from pole position at a circuit where the winner has started in the top slot for all of the past decade. However, the new moveable rear wing (DRS), kinetic energy recovery system and quick-wearing Pirelli tyres should make the race far less predictable with plenty of overtaking and pitstops expected.
"I'll have a good sleep tonight, come back and do the best job I can tomorrow," Webber said after his first pole since Belgium last August and seventh of his career. India's Narain Karthikeyan was 22nd.
Hispania refusalF1 stragglers Hispania have refused to rule out a protest against most other teams that could cast a cloud of uncertainty over Sunday's race. "I think some teams are running illegally, simple as that," team principal Colin Kolles said on Saturday.
Asked whether he might protest after the race, he replied: "Maybe, I don't know. I will see."