Having been kept at bay by the brilliant Dutch goalkeeper Sari van Veenendaal throughout the first half, the USA finally went ahead just after the hour as Rapinoe stroked home from 12 yards to end the tournament as joint top scorer on six goals.
There was an air of inevitability about the pink-haired 34-year-old, the star of this World Cup on and off the field, putting the USA ahead.
It also seemed inevitable that the breakthrough goal here should come from a VAR-awarded penalty, with French referee Stephanie Frappart initially giving a corner before pointing to the spot following a review.
The whippet-like Lavelle, another stand-out performer over the last month, got the second in the 69th minute, killing off Dutch hopes of a comeback.
The victory underlines the USA's status as the dominant force in international women's football as they claim the World Cup for the fourth time in eight editions.
The USA were already the first team to appear in three consecutive finals, and Jill Ellis becomes the first coach to win back-to-back World Cups in the men's or women's game since Italy's Vittorio Pozzo in the 1930s.
The USA had been the only non-European team to make it to the quarter-finals here, but they had already ended the hopes of the hosts and England before denying the Dutch a dream double success, two years after they won Euro 2017 on home soil.
Whether the Americans can continue this domination on to the next World Cup remains to be seen, not least because Rapinoe is already in the twilight years of her career.
She was brought back into the starting line-up here by Ellis having sat out the victory over England in the last four due to a hamstring problem. She later went off to a loud ovation from the massed ranks of USA fans.
The FIFA Women’s World Cup is held since 1991 when it was organized by China. The championships are held every four years, initially with 12 teams, today with 24.
The US today won its fourth world Championship. Germany has won twice, Norway, and Japan each one time.