More than 20 international delegations will attend the ceremonies, first in Jerusalem and then near the Gaza Strip.
US Vice-President Joe Biden will meet Israeli leaders during his visit.
Thousands of mourners paid their final respects on Sunday when his coffin lay in state outside parliament.
Prime Minister Benjamin Netanyahu told a cabinet meeting that Ariel Sharon was "first and foremost a warrior and a commander, among the Jewish people`s greatest generals in the current era and throughout its history".
His active role in four wars, from Israel`s independence in 1948 until 1973, and later in government as the man who ordered the 1982 invasion of Lebanon, meant he was also widely loathed across the Arab world.
Palestinians saw him as a war criminal, because of the 1982 massacre by Christian Phalangist militia at the Sabra and Shatila refugee camps. An Israeli inquiry found him responsible for failing to prevent the killings.
But months before the stroke that left him in a coma in January 2006, he guided Israelis through a unilateral withdrawal from the Gaza Strip, with the declared aim of easing tensions with the Palestinians.
Ehud Olmert, who took over from him as prime minister, has told the BBC that had he remained in office, Mr Sharon would not have stopped at Gaza but would have pulled out of most of the occupied territories.
"He thought that the territories were essential for the security of the state of Israel. When he found out that the security of the state of Israel perhaps could be served better by not being in all of those territories he then drew the necessary, inevitable conclusions," said Mr Olmert.
On Sunday evening, after the Israeli public had paid their respects to the 85-year-old ex-prime minister outside the Knesset, Israel`s parliament, an honour guard took his coffin into the building ahead of Monday`s memorial service.
Dignitaries from around the world are due to attend the Knesset memorial service, including Mr Biden, Russian Foreign Minister Sergei Lavrov, Middle East international envoy Tony Blair, Czech PM Jiri Rusnok and German Foreign Minister Frank-Walter Steinmeier.
Ministers and officials are also expected from several other countries, although no-one will attend from the Arab world, Africa or Latin America.
The main road from the airport to Jerusalem is being closed during the morning rush hour because of the arrival of international delegations.
The state funeral inside the Knesset will be broadcast on TV. Afterwards, Mr Sharon`s body will be taken in a funeral cortege for a brief military ceremony at Latrun, west of Jerusalem, where he was severely wounded in the 1948 war of independence.
His final journey will be to the Sycamore ranch he owned near Sderot, close to Gaza. Mr Sharon will be buried beside his wife Lili, who died in 2000.
Because of its proximity to Gaza, three security rings are being placed around the farm. The inner ring closest to the grave will be for family and invited guests alone, the second will be open to the public and the third will be a security measure surrounding the perimeter.
An unconfirmed Israel TV report said Israel`s Iron Dome aerial defence system was being prepared in case of rocket attack.