Amorim has been in charge of Sporting since March 2020 but has seen his name among the rumour mill at various stages this season when Chelsea and Aston Villa were in the hunt for new managers.
Amorim led Sporting Lisbon to their first Primeira Liga title in 19 years when he won the Portuguese top flight in the 2020/2021 season.
Although Sporting have endured a slightly tougher campaign this term, the club's hierarchy still firmly believe in his methods thereby extending his contract.
Sporting Lisbon were fourth on the league standings, 12 points behind leaders Benfica, before the league went on hibernation for the FIFA World Cup to take place.
They will play in the Europa League when club football resumes after finishing third in their Champions League group behind Tottenham Hotspurs and Eintracht Frankfurt.
"This renovation demonstrates a lot how Sporting CP works today: with discretion, efficiency and direction," president Frederico Varandas said.
"It is also a very strong sign of how today Sporting CP is a strong and stable club, with stability being the basis of all success.
"A contract of this length always obliges the people who sign it to see themselves 100 per cent in the sporting project and that there is extreme trust between both parties.
"As president of Sporting CP, I can only be very happy that we have a contract until 2026 with one of the best coaches in the world and that we will continue to make Sporting CP grow."