Davante Adams scored two touchdowns on the back of 160 receiving yards, while Aaron Jones rushed for 62.
Packers quarterback Aaron Rodgers threw the two TD passes to Jones as he went 16 of 27 for 243 yards.
Russell Wilson (21 of 31 for 277 yards and a TD) and the Seahawks came to life in the second half, but it was too little, too late.
The Packers made their dominance count in the first half, with Jones scoring two second-quarter touchdowns.
But the first score came through Adams, who was found by a 20-yard Rodgers pass after an eight-play, 75-yard drive early in the encounter.
Jason Myers' 45-yard field goal put the Seahawks on the board, but the Packers were 21-3 up at half-time.
After two lengthy plays for 75 and 60 yards, Jones pushed over from close range to put Green Bay in control.
Seattle delivered a much-needed response through Marshawn Lynch early in the third quarter, only for Rodgers and Adams to combine again, a 40-yard TD pass restoring the Packers' 18-point lead.
Wilson's short TD pass to Tyler Lockett late in the third quarter brought the Seahawks back into the clash before Lynch bulldozed his way over from close range in the fourth to bring Seattle within five.
But that was as close as they got as Green Bay moved to within a win of Super Bowl LIV.