The top US diplomat met for nearly an hour in the early morning with Crown Prince Mohammed bin Salman at the royal's farm residence in the Riyadh area, a US official said.
"Very productive," Blinken said when asked about the meeting after returning to his hotel.
Blinken "highlighted the United States' unwavering focus on halting terrorist attacks by Hamas, securing the release of all hostages and preventing the conflict from spreading," State Department spokesman Matthew Miller said.
"The two affirmed their shared commitment to protecting civilians and to advancing stability across the Middle East and beyond," Miller said.
Prince Mohammed highlighted Riyadh's diplomatic outreach "to calm the situation," the official Saudi Press Agency (SPA) reported, an effort that has involved calls to regional leaders including Iranian President Ebrahim Raisi.
FILE - US Secretary of State Antony Blinken returns to his hotel in the Saudi capital Riyadh after meeting with Saudi Crown Prince Mohammed bin Salman on October 15, 2023.
He also reiterated the Gulf kingdom's condemnation of attacks on civilians and "vital interests that affect their daily lives," while stressing the need for Palestinians to "obtain their legitimate rights and achieve just and lasting peace," SPA said.
Blinken has been touring the region after Hamas fighters infiltrated Israel from the blockaded Gaza Strip on October 7 and killed 1,300 people, mostly civilians, and took about 150 hostages.
The attack sparked a massive retaliatory campaign targeting the Islamist group in Gaza that has killed more than 2,300 people.
Before the violence, the Saudi crown prince had spoken of progress in US-led diplomacy to normalise relations between Saudi Arabia and Israel.
Saudi Arabia has put the process on hold after the violence, and Blinken has said that disrupting Saudi-Israel normalisation efforts may have partly motivated the Hamas attack.
The kingdom is the guardian of Islam's two holiest sites, making recognition a historic coup for Israel, which in 2020 normalised relations with three other Arab states including the United Arab Emirates.
- Next stop: Egypt -
As part of a package, Saudi Arabia -- which like Israel has tense relations with Iran's Shiite clerical state -- has been seeking security guarantees from the United States, its longtime partner and consumer of its oil.
But Prince Mohammed is deeply controversial in the United States, where intelligence linked him to the 2018 killing and dismemberment of Jamal Khashoggi, a US-based Saudi journalist.
Riyadh denies this, blaming rogue operatives.
President Joe Biden -- who once vowed to make the kingdom a pariah -- drew protests at home after a visit to Saudi Arabia last year when he shared a friendly fist-bump with Prince Mohammed.
FILE - Egypt's President Abdel Fattah al-Sisi (R) meets with US Secretary of State Antony Blinken in Cairo on October 15, 2023.
The State Department said Blinken and the crown prince also discussed Yemen, where an uneasy peace has been holding between the Saudi-backed government and Iranian-backed Huthi rebels.
They also addressed Sudan, on which the Saudis have been working with the United States to mediate between warring generals, with limited success.
Blinken will travel later Sunday to Egypt, the sixth Arab country he will visit as he seeks to pressure Hamas and prevent the war from spreading.
Egypt is a key intermediary between Israel and Hamas, and US officials say Cairo worked on an arrangement to let US citizens leave the Gaza Strip but that Hamas impeded their movement on Saturday to the sole border crossing at Rafah.