Ian Gorham, 44, has decided to step down no later than 30 September 2017, at which time he would have been in the role for over 7 years.
Chris Hill, currently the group chief financial officer, will become deputy chief executive from 1 October 2016, with the intention that Chris will be confirmed as chief executive following his departure.
During Mr Gorham’s tenure, client numbers have risen by over 500,000 from 330,000 to 836,000 and profit before tax has risen 154% from £86.3m to £218.9m.
Mr Gorham said: “Now is the correct time for natural succession, as we look forward to an exciting future. I am proud of our collective achievements and would like to thank our clients, my colleagues and all those that have contributed to Hargreaves Lansdown's amazing story so far for their support.
“I am confident that Hargreaves Lansdown will go from strength to strength in the next phase of its growth."
He said: "I have loved leading Hargreaves Lansdown and working with the great clients, colleagues and shareholders of this Group. I have put my full energies into the business, something a unique Group of the quality of Hargreaves Lansdown demands.
“I believe the Group is in excellent hands and that shareholders and clients shall be best served by new zest being applied to the Group's activities.”
Mike Evans, Chairman, said: "Ian has done a fantastic job of leading Hargreaves Lansdown to its current position of a market leading successful FTSE 100 business, serving the investment needs of 836,000 clients and looking after £61.7 bn of the UK public's assets. The Board thanks Ian for his outstanding contribution to Hargreaves Lansdown. We are delighted to appoint Chris Hill as our Deputy Chief Executive."
Mr Hill said: "I am honoured to be appointed deputy chief executive of Hargreaves Lansdown, one of Britain's great businesses and success stories. I look forward to working with our clients, colleagues and shareholders to build on the exceptional accomplishments of this group to date."