Mr Trump's first stop on a week-long overseas trip is meant to put in place a framework and fill in details for an enhanced partnership with traditional US Arab allies that involves them taking on a greater share of the responsibility for regional security.
"It's nearly always true that when a president goes on a big foreign trip, especially one that has some important summits. that that dominates the news and knocks most other stuff out", said Republican strategist Charlie Black.
Trump - whose face, alongside a picture of King Salman, was displayed on billboards across the city in anticipation of his arrival, under the slogan "Together We Prevail" - received a red carpet reception at the airport, where Saudi air force armed with rifles stood at attention awaiting Air Force One.
In a further sign of respect to Trump, the king traveled with him in a large motorcade from the airport to the Ritz Hotel, the first non-Trump-branded property that the president has stayed at since taking office.
According to an explanation by the Economist, Saudi Arabia has been known for its varied versions of cloaks for women (jijab, niqab, burqa) that derive from the nation's foundational observance of "sharia" as state law.
An airman salutes Friday as Air Force One (left) with President Donald Trump aboard taxis for takeoff with the duplicate plane at Andrews Air Force Ba.
President Trump's Saudi royal hosts have pulled out all the stops for this visit. This week, the Justice Department named a special counsel to investigate Russian meddling in last year's election, including potential ties between Trump associates and Russian officials.
That move followed the president's surprise firing of FBI Director James Comey earlier this month, and his acknowledgment that frustration with the ongoing Russian Federation investigation factored into his decision.
Pictures later revealed Melania was at the meeting with the King.
The visit kicks off an ambitious worldwide debut for Trump.
My first stop will be Saudi Arabia the heart of the Muslim world.
Trump wants Gulf states in particular to do more to tackle extremists such as the Islamic State jihadist group.
Awad said it is still possible for Trump to succeed in his outreach, but stressed that his campaign rhetoric will "not easily be erased" by one speech.
While his predecessor Barack Obama was viewed with suspicion by Gulf Arab states for his tilt towards their regional rival Iran, Trump is likely to take a harder line against Tehran.
Trump was joined by first lady Melania Trump, his daughter Ivanka and his son-in-law and senior adviser Jared Kushner.
That might be surprising considering some of the ways Trump disparaged Saudi Arabia as a presidential candidate.
Donald Trump and King Salman bin Abdulaziz al-Saud in Riyadh on May 20.
Trump's relations with the wider Islamic world are still strained by his travel ban targeting several Muslim-majority nations.
US President Donald Trump has said his first trip overseas to "lands associated with three of the world's great religions" is aimed at uniting the civilized world in a fight against terrorism. An early draft of his speech does not contain the phrase "radical Islamic terror", a term which Trump has emphasized back home.
Israel was in an uproar earlier this week after USA officials confirmed Trump shared highly classified intelligence about the Islamic State group with senior Russian officials visiting the White House. He also read newspapers and caught a little sleep, said his chief of staff Reince Priebus.