Paul Pogba, Dimitri Payet and Antoine Griezmann were also on target in a one-sided romp at the Stade de France that proved a nightmare end to Iceland's improbable dreams of success.
Having fairly comfortably eased past England into the quarter-finals, Iceland, the smallest nation ever to have qualified for the European Championship, with a population of 330,000, were 4-0 down inside the first half.
France, who had not been past the quarter-finals since they won the tournament in 2000, eased off and cruised home.
Coming into the game, Iceland were praised for a rigidly well-organised defence while France had found first-half goals hard to come by, with their previous six coming after the break.
It was a matter of minutes, however, before both of those traits to be swept aside, as France set about picking their way through gaping holes in Iceland's previously solid rearguard.
Having defended so admirably against England, Iceland were 2-0 down inside 20 minutes through two of the oldest and simplest tricks in the football playbook.
Long ball
The second goal was a simple corner to the far post that the soaring Pogba headed emphatically home.
It seemed as though the contest was already effectively over when Payet turned the screw two minutes before halftime, sweeping home a low left-foot strike from the edge of the area for his third goal of the tournament.
Yet worse was to come for Iceland as Griezmann twisted the knife on the stroke of halftime, latching onto a through ball after Giroud's dummy to race clear and chip the advancing Halldorsson to become tournament top scorer with four goals.
A simple lofted free kick from Payet three minutes later allowed Giroud to dart in front of the keeper and flick his header into the unguarded net.
With six minutes remaining, Bjarnason pulled another goal back for Iceland with a header but the tie, and Iceland's hopes of extending their dream run, were over as France looked forward to facing old rivals Germany in Marseille on Thursday.