Saudi Arabia has been the key backer of Sisi since the then-army chief in 2013 overthrew his Islamist predecessor Mohamed Morsi, whose Muslim Brotherhood movement was viewed with suspicion by Riyadh.
It has pumped billions of dollars in aid and investment into Egypt's battered economy, and the two heads of state are expected to ink more investment agreements tomorrow amounting to about USD 1.7 billion.
Live footage on state television showed Sisi greeting the 80-year-old Salman at Cairo airport, before heading off in a convoy to the presidential palace.
Salman is expected to address the Egyptian parliament on Sunday, state media reported.
Egyptian media gave full coverage of the visit, with state television welcoming Salman to his "second country" and playing celebratory music as his plane touched down in Cairo.
"This is the first official visit by King Salman, whose valuable and honourable positions in support of Egypt and its people will never be forgotten," the presidency said in a statement before Salman's arrival.
The visit follows months of reports in both Saudi and Egyptian newspapers of strained ties over Cairo's unwillingness to participate fully in the Saudi-led war against Iran-backed Shiite rebels in Yemen.
Egypt had announced it would back Saudi Arabia with ground troops if needed, but appears to have balked at the prospect of becoming mired in the conflict.
Sisi's close relationship with Russian President Vladimir Putin, who militarily backs Syrian leader Bashar al-Assad against Saudi-supported rebels, has reportedly also caused friction with Riyadh.
For Saudi Arabia, which is in competition with regional rival Iran, keeping Egypt under its aegis is crucial.
