The UK and Saudi Arabia are set to agree closer ties in areas including defence, security, intelligence and trade.
Britain is also set to become a "leading partner" in the kingdom's efforts to reform and modernise under its "Vision 2030" programme.
Over the next 13 years, the Middle Eastern country is planning to reduce its dependence on oil, boost the number of women in work and develop sectors such as health, education and culture.
It comes as Theresa May is due to meet the King Salman in Riyadh during her visit to boost links.
The UK will help Saudi Arabia with "building a reformed ministry of defence, reviewing Saudi defence capabilities and joint working across the Saudi armed forces", the Government said.
Mrs May said: "These new partnerships, on defence and security, trade and the economy, education, healthcare, culture and sport, evidence the breadth and depth of the UK's relationship with Saudi Arabia.
"We are firm supporters of Saudi Arabia's Vision 2030, an ambitious blueprint for internal reform that aims to deliver greater inclusivity for all Saudi citizens, something we agree is essential to Saudi Arabia's long-term stability and success.
"As a world leader across a range of sectors, the UK is well placed to help Saudi Arabia deliver these vital reforms."
The Prime Minister insists it is in the national interest to have good relations with the country despite its controversial record on human rights.
She has denied Britain is selling its principles for trade deals, despite widespread criticism over UK arms deals with the kingdom.
Mrs May has faced calls to suspend the sales following claims of human rights abuses in the Yemen conflict under the Saudi-led coalition bombing campaign.
Labour has called on Mrs May to halt arms exports to the state, urging her to back an independent investigation into alleged war crimes in Yemen.
The state has also faced criticism over its poor record on women's rights.
But the PM insisted the UK must engage with the Saudis rather than criticise from the sidelines.
She told Sky's Faisal Islam : "We have no difficulty in raising hard issues, with those that we meet, be it in Saudi Arabia and elsewhere around the world.
"What matters is that we have the relationship and the engagement that allows us to do that."
It comes as the International Trade Secretary faces criticism for preaching "shared values" with the Philippines as he met the president Rodrigo Duterte, who has boasted of killing suspected criminals.
More than 7,000 people have been killed in Mr Duterte's campaign against drugs and the president has urged the public to kill drug addicts.
In an article for Philippines' Business World, Dr Liam Fox wrote: "The UK and the Philippines have a well-established and strong relationship built on a foundation of shared values and shared interests and we want this partnership to continue to flourish."
Labour MP Harriet Harman, who is chairwoman of the joint committee on human rights, told The Guardian: "There is a real danger that in our desperation to conclude trade deals respect for human rights, which is in every EU contract, will just go out of the window."