Photo gallery: Thunder over Cardiff and Newport as Nato planes fly over
The 22-plane flypast - with aircraft from nine nations - whooshed over the Welsh capital first, led by an RAF Typhoon jet.
It was flanked by two Polish Mig-29s and followed by a convoy of fighter planes from the USA, Germany, Canada, France, Denmark, Portugal and the Netherlands.
More: Red Arrow pilot tweets cockpit view of Nato flypast
More: Watch our video of the spectacular Nato flypast
More: Obama and Cameron watch Nato flypast at Celtic Manor
Also taking part in the display was the RAF's largest and newest aircraft, Voyager - which has a span of more than 197ft (60m) and can act as a "flying petrol station" for other planes.
Topping off the show were the famous Red Arrows trailing their signature tricolour smoke.
Number 10 has released this 'hyperlapse' video showing the flypast.
Scores more onlookers were dotted on the hilltop across the water in Penarth, while in Newport people gathered on the Millennium Footbridge as the flypast went over the south of the city centre.
World leaders, including US President Barack Obama, Prime Minister David Cameron and German Chancellor Angela Merkel, were all smiles as they watched the display outside summit venue the Celtic Manor.
Nato leaders posed for a family photo at the Nato summit dinner at Cardiff Castle last night.
Watch the moment President Obama met the Prince of Wales at Thursday's reception:
President Obama met the Prince of Wales as he hosted a reception with schoolchildren in Newport.