The bank also reappointed Hassana Investment Company's chief executive Saad Al Fadly as vice chairman.
The non-executive appointments were made after Sabb received a notice of no objection from the Saudi Arabian Monetary Authority, the lender said on Wednesday in a filing to the Tadawul bourse, where its shares are traded.
Sabb is the fourth-biggest lender in the kingdom and had a market value of $21.4 billion as of Wednesday.
The bank was founded in 1978 as a Saudi joint stock company, with HSBC retaining a minority stake in it.
It reported a net profit of $926 million in the first nine months of 2022, up 26 per cent annually from the same period in 2021.
Sabb was the first organisation in the kingdom to have a green deposit, with the funds deposited with HSBC in the UAE and used entirely for the purpose of financing green initiatives.
The lender issued the first $3.76 billion green loan for the Red Sea Development Company, now Red Sea Global, in 2021.
It entered into a $5 billion merger with Saudi competitor Alawwal Bank in June 2019. Ms Olayan was appointed chairwoman of Sabb in January 2020, after the merger.
She holds a master's degree in business administration from Indiana University in the US and an honorary doctorate in law from Trinity College in Dublin.
In 2004, Ms Olayan became the first woman to join the board of a listed Saudi company when she was elected to the board of Alawwal Bank and served as deputy chairwoman, according to Sabb's website.
She also served as chief executive of Olayan Financing Company for more than 35 years, and presently heads its executive committee.
Saudi Arabia is working to increase women’s participation in the labour force as part of Crown Prince Mohammed bin Salman's Vision 2030 plan to reduce the economy's dependence on oil revenue.
The workforce participation of Saudi women has been steadily rising.
Unemployment among Saudi women fell to 20.5 per cent in the third quarter of 2022, from 21.9 per cent in the same period in 2021, according to the latest data by the General Authority for Statistics.
Saudi women made up 37 per cent of the kingdom's labour force in the third quarter of 2022, up from 34.1 per cent in the same period of 2021, the Gastat data shows.
Giving women driving licences and better access to the workforce will improve mobility and unlock an underutilised resource.
It is also expected to boost productivity, income and economic growth, and drive the expansion of Saudi Arabia's non-oil private sector, analysts have said.
Sabb's latest appointments come amid a strong performance by banks in Saudi Arabia.
The aggregate net profit of Saudi Arabia's 10 largest banks increased by 9.3 per cent on quarterly basis in the third quarter of 2022, driven by higher interest rates and lower impairment charges, according to professional services consultancy Alvarez & Marsal.
The banks' cumulative net income for the three months to the end of September rose to 16.5 billion Saudi riyals ($4.4 billion), the consultancy said in its latest Saudi Arabia Banking Pulse report.