Women occupied 19% of board seats in Thailand, trailing the global average of 23.3% and slightly behind the Southeast Asian average of 19.9%, according to Deloitte Global's 2023 Women in the Boardroom report.
However, Thailand was No.2 in Southeast Asia for female chief executives, equal with Singapore at 11.9% and behind the Philippines at 12%.
The report was based on a dataset covering 18,085 companies and 206,506 directorships spanning Asia-Pacific, the Americas, Europe, the Middle East and Africa. The data was collected on March 17, 2023.
The percentage of board seats held by women in Southeast Asia increased from 17.1% in 2021 to 19.9% in 2023.
Women hold 23.3% of board seats globally, up 3.6 percentage points year-on-year.
Only 8.4% of the world's boards are chaired by women, and 6% of chief executives are women, according to the report.
Without greater focus and action, gender parity in the boardroom is unlikely to be achieved before 2038, noted Deloitte.
To achieve parity, a wide range of stakeholders need to devote greater attention and action to help corporate boards more accurately reflect the societies in which they operate, while boards will need to take action and ask the right questions, said the report.
"The business case for diversity is clear: companies with more diverse boards have shown that they tend to perform better financially," said Anna Marks, Deloitte Global chair.
"Despite that, it is clear a tangible increase in momentum is needed to reach gender parity in the boardroom. With women still underrepresented on company boards globally, that step change in momentum will require organisations and investors to do more to realise the benefits that diverse boards can bring."
Ms Marks said government action has yielded results in advancing parity at the board level.
For instance, five of the top six countries with the highest percentage of women serving on boards have quota legislation, ranging from 33% (Belgium and the Netherlands) to 40% (France, Norway and Italy).
Continued government initiatives, such as the use of targets and disclosures, have also driven progress, she said.
In terms of Southeast Asia, Malaysia was the leader for the percentage of board seats held by women (28.5%), driven by initiatives such as the "one woman on board" quota for listed companies.
Although listed companies in Malaysia have yet to meet the target of 30% women directors set in the Code on Corporate Governance, there has been headway in women's representation in boardrooms.
Board seats held by women in Asia-Pacific only averaged 14.8%, according to the report, an annual increase of 1.2 percentage points, lower than the uptick for Southeast Asia.
A similar trend occurred with female board chairs in Thailand, rising 3.2 percentage points annually.
Thailand registered 7.2% women board chairs, beating the Asia-Pacific average of 6.9% but lagging the global average of 8.4%.