Ruth Hunt, chief executive of the LGBT rights charity Stonewall, is to step down in August.
A statement from the charity said Hunt, who has worked at Stonewall since 2005 and was promoted to the top job in August 2014, would be leaving to pursue "a new opportunity".
A Stonewall spokesman was unable to give further details on Hunt’s next move, but she said in a blog post on the charity’s website that it was time for someone else to take the charity "into the next chapter".
The statement from the charity said Hunt had played a central role in many of its key achievements in recent years, including development of the charity’s Education for All campaign, designed to reduce homophobic, biphobic and transphobic bullying in schools, the growth of the charity’s empowerment function, which has enabled LGBT people to act as leaders and role models in their workplaces and communities, and leading a major consultation to enable the charity to become fully trans-inclusive.
Stonewall’s income has grown from £5.4m to £8.7m during Hunt’s time in charge, while its staff team has more than doubled to 160 people over the same period.
Jan Gooding, chair of Stonewall, said Hunt had been a "visionary, bold and inspirational leader" during her time at the charity.
"When Ruth took the reins of the organisation in 2014, Stonewall was a very different place," said Gooding. "Over the course of her tenure, she has changed the organisation’s culture, expanded our remit and shown an unequivocal commitment to supporting parts of the LGBT communities that have traditionally been excluded.
"Ruth will leave with the knowledge that she has significantly transformed Stonewall for the better and has provided an exciting opportunity for a strong and forward-thinking leader to step in and take the helm during a new strategic period."
Hunt said the past 14 years at the charity had been transformative for her, both personally and professionally.
"Recognising the diverse experiences and needs within LGBT communities, exploring intersectional identities and looking deeply at multiple forms of discrimination has not always been a comfortable conversation for Stonewall to have, but it has been a vital one," she said.
"Expanding our work to ensure we are more closely speaking alongside and sharing power with these communities is a journey we are still on, and one that I am confident will excite a new leader.
"I could not be prouder to have led this amazing organisation for the past five years and look forward to seeing it – and all the amazing people who work for it – go from strength to strength in years to come."