Cairo said it offered its full support to the reconciliation move, which it described as a "huge step towards Arab solidarity".
"We look forward to a new era that would end past disputes and spread hope and optimism to our peoples," Egyptian President Abdel Fattah al-Sisi's office said.
The Egyptian army's overthrow last year of Islamist president Mohamed Morsi strained ties with Qatar, which had been a key Morsi backer.
His ouster led to differences among Gulf states, with the United Arab Emirates and Saudi Arabia hailing his replacement, while Qatar repeatedly denounced it.
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Egypt had already withdrawn its ambassador in February, although Doha has kept its envoy in Cairo.
On Sunday, Gulf leaders agreed to return their ambassadors to Doha, signalling an end to the dispute.
Saudi King Abdullah today urged "Egypt, the people and leadership, to seek with us the success of this (reconciliation) move as part of Arab solidarity," according to the official SPA news agency.
He said the kingdom looked forward "to the start of a new phase of consensus" among Arab nations and voiced hope for "security and stability for our people amid these circumstances and challenges" facing the region.
Ties between Cairo and Doha are also strained over an Egyptian court convicting and jailing three reporters from Qatar-based Al-Jazeera television for backing Morsi's Muslim Brotherhood and spreading false information.
Cairo considers Al-Jazeera as Doha's voice after the channel repeatedly criticised its crackdown on Morsi's supporters that has left at least 1,400 people dead since his ouster.
Bahrain, Kuwait, Qatar, Saudi Arabia and the UAE have all joined or are supporting US-led air strikes against IS in Syria.