Having lost to South Africa in the final of the Paris Sevens last week, Scotland went one step further in London thanks to second-half tries from Hugh Blake and Scott Riddell.
The Blitzboks, meanwhile, had the chance to lift the championship trophy that was secured with last week's victory in Paris
Despite the loss, England managed to secure second place in the overall standings -- the side's best finish since 2007.
"We're really, really pleased to get second in the World Series," head coach Simon Amor told CNN.
"There's an awful lot of credit that goes to the players and the staff. The progress we've made this season has been really encouraging.
"South Africa have been outstanding this year, they're worthy champions. To be in eight or nine finals is just phenomenal. They set a pretty high benchmark."
England had the upper hand in the first half of the final after a superb solo try by winger Dan Norton, who recently became the highest try scorer in rugby sevens history.
But stubborn Scottish defense kept the home side at bay, creating a platform for the Scots to lift just their second ever World Series title after also triumphing in London last year.
On a day when rivals seemed destined to meet, Canada narrowly edged out USA 22-19 in an all-North American battle for third place.
With the season drawing to a close, Amor took time to toast what's been a successful period for the Sevens World Series, visiting 10 locations and seeing five different sides lift trophies since the first tournament took place in Dubai in December.
"The game's exploded. With the vibrancy of the stadiums and the standard of rugby -- it's a very exciting time to be in the game," he said.
"It's tough as a coach. It's been up and down, but it's a very exciting time for the sport. It's brilliant the game is growing globally so much. We can really show what a brilliant sport it is to the world."