The midfielder's crucial 95th minute penalty secured a 2-1 win over Congo in Alexandria, sparking jubilant scenes.
Salah has been in fine form for the Reds this season too, scoring six goals and providing two assists in just 11 games.
He had earlier put Egypt ahead, only for Congo to seemingly spoil the party with an equaliser three minutes from time.
But former Chelsea player Salah, 25, stepped up to convert the spot kick and send the Pharaohs to Russia 2018.
“I can’t really express how I feel,” Salah told Ahram newspaper after the game.
“I don’t quite talk so much but I’m really proud.
"Today we realized a long-awaited dream.
“That was to me a dream come true, whether as a footballer or an Egyptian citizen and fan.
"I’m proud I made the Egyptians happy today by scoring today twice against Congo.
“The game was a difficult one tonight and all the qualifiers were difficult games as well, today there is no big difference between every team and the other.”
Salah also told Ahram how he had stayed calm amid a frenzied atmosphere when taking the penalty.
He added: “When I stepped up to take the penalty, I didn’t think of anything but scoring and winning the game.
“The most difficult moment in my life was when the fans fell silent following Congo’s equalizer but thank God we finally realized a childhood dream of my own.”
Jurgen Klopp brought Salah to Liverpool in a £37m deal from Roma this summer.
Liverpool host Manchester United at Anfield on Saturday (12:30), once the international break has ended.
