Sisi arrived from the United Arab Emirates where he had addressed a conference about the fight against "terrorism".
He was met by the heir to the Saudi throne, Crown Prince Salman bin Abdulaziz, at King Abdulaziz Medical City where the monarch was admitted for tests on December 31.
The royal court announced on January 2 that King Abdullah had pneumonia and was breathing with the aid of a tube.
Since then, there have been no updates on his condition but the official Saudi Press Agency has reported that numerous Saudi and foreign officials have been "reassured" about his health.
"President al-Sisi wished the Custodian of the Two Holy Mosques every health and quick recovery," SPA said, adding that Sisi then left the kingdom.
Saudi Arabia is home to two of Islam's holiest sites.
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King Abdullah has been a key financial supporter of Sisi's Egypt and an ally against Islamic extremism.
Abdullah was the first head of state to visit Cairo after Sisi's election win last May, and last August the Egyptian leader reciprocated with a trip to the Saudi Red Sea city of Jeddah for talks with Abdullah.
The military, then headed by Sisi, in July 2013 overthrew Egypt's elected Islamist president Mohamed Morsi who hailed from the Muslim Brotherhood, a move which led to differences among Gulf states.
Qatar was accused of destabilising the region by supporting Islamist groups including the Brotherhood -- branded a "terrorist" organisation by Saudi Arabia and the UAE.
Saudi mediation late last year helped resolve the dispute between Qatar and its Gulf neighbours and led Doha to pledge its "full support" for Egypt.
Ties improved as regional officials expressed concern over the rise of the Islamic State extremist group in Syria and Iraq.
Bahrain, Kuwait, Qatar, Saudi Arabia and the UAE have all joined a US-led air campaign against IS in Syria.