Talks between the two nations, held alongside a business forum, "marked the intense relations of friendship and confidence... and the shared will to take them even further," a final statement said.
The agreements include contracts and letters of intent between the countries whose economic and political relations have grown under President Francois Hollande.
The statement says both sides will conclude negotiations -- with an end-of-year target date -- to provide fast patrol boats for the Saudi navy.
Separately, the kingdom's Public Investment Fund has allocated $2 billion for French investments focussed on renewable energy and small- and medium-sized enterprises, it said.
The lifting of an embargo on French beef, imposed over "mad cow" disease, will allow 37 French firms to resume exports to the Gulf kingdom, Valls' office said.
Other deals under discussion could cover telecommunications and surveillance satellites, urban transport and energy.
France is the third-largest investor in Saudi Arabia, and Valls said he expects additional deals to be finalised.
"We don't doubt for one instance that these letters of intent will be confirmed," said Valls.
The announcements came during the third high-level visit this year by French officials to the world's largest oil exporter.
France has boosted ties with the conservative Islamic kingdom -- the Arab world's largest economy -- despite persistent criticism from rights activists of its record on civil liberties.
For Saudi Arabia, expanding ties with France are part of an effort to build alliances beyond its traditional defence partner the United States, to counter Riyadh's regional rival Iran.
Valls, accompanied by Defence Minister Jean-Yves Le Drian, was on a regional tour which included Jordan and Egypt.
Foreign Minister Laurent Fabius joined them in Riyadh for the talks.
- Regional weapons deals -
Hollande visited in January to pay his respects after king Abdullah died, and returned in May for a regional summit.
The negotiations for patrol boats follow a series of weapons sales Paris has made in the region this year.
On Saturday, Egypt signed a deal with France to buy two Mistral warships originally ordered by Russia.
According to French government sources, Egypt will receive "significant" Saudi financing for the purchase.
France this year also sold 24 Rafale warplanes to Egypt and Qatar.
In Cairo, Valls highlighted joint efforts against extremism, saying: "We all have a common enemy -- Daesh."
He was using an Arabic acronym for the jihadist Islamic State group which has seized territory in Syria and Iraq where it has carried out widespread atrocities, and inspired attacks elsewhere.
Both France and Saudi belong to the US-led coalition that has bombed IS, which also claimed responsiblity for bombings in the kingdom this year.
Riyadh and its Sunni-dominated neighbours accuse their Shiite regional rival Iran of meddling in Iraq, Syria, Lebanon and Yemen.
Since March, Riyadh has led an Arab coalition backing Yemeni forces, first with air strikes and now also with ground troops, against Iran-supported Huthi rebels who had seized much of Yemen.
Human rights watchdogs have repeatedly criticised the coalition's aerial bombardment of Yemen, saying they did not strike military targets.
Saudi Foreign Minister Adel al-Jubeir told reporters the Huthis and their allies are the only ones who can bring an end to the war. He called for them to join a political process.
Fabius said France supported efforts towards a political solution but needed "all parties" to agree to talks.
The French delegation was discreet on the subject of human rights, but Valls told reporters he "called for clemency" for Ali al-Nimr, a member of the minority Shiite community facing the death penalty.
Nimr was just 17 when arrested in February 2012 after taking part in pro-reform protests.