The German captain’s opener was quickly cancelled out by Merle Frohms’ own goal, but Popp’s towering header 14 minutes from time sent the eight-time winners into another final at Wembley.
Popp had been at risk of missing the European Championship for a third time due to injury, but the Wolfsburg striker proved her fitness in time after two knee surgeries and has gone on to be the star performer of the tournament.
The 31-year-old’s double took her level with England’s Beth Mead on six goals in the battle for the Golden Boot, matching the record for a single women’s European Championship held by Inka Grings from Euro 2009.
That tournament ended in a German rout over England in the final and Die Nationalelf will be hoping for a repeat as they aim to upset the hosts in front of a sell-out crowd of 87,000.
In contrast to Germany’s pedigree at the women’s Euro, France were in the last four for the first time.
Les Bleues were left to regret a series of missed chances early in the second half as they lacked a clinical goalscorer without the injured Marie-Antoinette Katoto.
Popp gave France a warning of what was to come when her powerful free-kick from the edge of the area was brilliantly clawed away by Pauline Peyraud-Magnin.
The French goalkeeper was helpless five minutes before half-time when Svenja Huth’s cross picked out Popp, who smashed home a volley into the roof of the net.
That goal ensured the Germany skipper became the first woman to score in five consecutive European Championship games.
But the lead lasted just five minutes in unfortunate circumstances for Frohms.
Kadidiatou Diani’s fierce strike from outside the box came crashing off the post into the back of the Wolfsburg goalkeeper and into her own net.
Frohms more than made amends at the start of the second period with a brilliant save to her left to turn Wendie Renard’s header behind.
Selma Bacha’s goalbound effort also rebounded behind off Kathrin-Julia Hendrich’s face and Diani’s shot from a narrow angle stung the palms of Frohms.
But France failed to make that bright spell count and were made to pay by Popp’s predatory instincts.
Another Huth cross was hung high into the Milton Keynes sky and Popp timed her leap perfectly to power a header into the ground and past Peyraud-Magnin.