As expected, the 77-kilometres eighth and final stage finished in a bunch sprint, with Ewan (Mitchelton-Scott) winning ahead of Fernando Gaviria (QuickStep-Floors) and Andre Greipel (Lotto-Soudal).
Germany's Greipel had won two stages earlier this week, but Ewan was triumphant on this occasion.
Alaphilippe protected his 17-second lead on Saturday's penultimate stage and completed victory ahead of Holland's Wout Poels (Team Sky) and Slovenia's Primoz Roglic (LottoNL-Jumbo).
Scott Davies (Team Dimension Data) was the highest-placed Briton in 12th place, one minute 54 seconds behind Alaphilippe.
Tour de France champion Geraint Thomas was 36th and four-time Tour yellow jersey winner Chris Froome was 85th after both played team roles this week.
Froome was riding in his first Tour of Britain since 2009, when the race visited Frome in Somerset. He has no plans to leave it another nine years before returning.
"It was a pleasure to race here. I'd love to come back here in the future," Froome said.
Froome, who won the Giro d'Italia in May and was second at the Tour behind Team Sky team-mate Thomas, and the Welshman have withdrawn from consideration for the Great Britain team for the Road World Championships in Innsbruck, Austria later this month.
For Froome it has been a gruelling season, which began with him contesting and later being cleared of an adverse analytical finding for elevated levels of salbutamol and included the birth of his second child.
Froome said: "I'm not where I need to be in order to be at a worlds like that."
Thomas, likewise, will be taking a rest, bringing his season to a close.
The 32-year-old, who on Sunday signed a new three-year contract with Team Sky, said: "Physically and mentally I am not ready for it.
"I was suffering like a dog for an hour and a half (today)."
