Addressing the opening session of parliament's new term, Sheikh Sabah said the boycott has greatly weakened the unity of the six-nation Gulf Cooperation Council (GCC), of which Qatar is a member.
GCC members Saudi Arabia, United Arab Emirates and Bahrain, in addition to Egypt, imposed a sea, land and air boycott of Qatar in June 2017 accusing it of ties to radical groups. Doha has repeatedly denied the allegations.
"It is no longer acceptable or bearable for the dispute that erupted between our GCC brethren to continue," Sheikh Sabah, 90, told parliament in his first public appearance since travelling abroad for medical treatment in early September.
Sheikh Sabah, who has been acting as a mediator to resolve the dispute, said the "row has weakened our capabilities and threatened our achievements", calling for a negotiated solution.
The Amir called for national unity in the face of regional developments and protests in several Arab countries.
He also hit out at the misuse of social media, saying it has created divisions in society.