Frank, who will edit all three titles, is currently director of digital content for JP, and served as The Scotsman’s assistant editor between 2010 and 2012.
He then spent three years as editor of his hometown paper the Evening News, before a restructure which saw Ian take on the editorial director role across the three titles and Frank become managing editor of the trio.
Frank, 46, said: “It is an enormous privilege to be at the helm of three great brands. The Scotsman is in its 200th year and has reported on every significant event in the country’s modern history.
“As we enter a period of further change, The Scotsman’s role as an independent and impartial voice in this debate will be more important than ever.
“Digitally, scotsman.com and edinburghnews.com have been strong platforms for many years. It is time to invest further focus and energy to take our online storytelling to a new level.
“I’m looking forward to returning to the newsroom and working with many of the most talented journalists in Scotland.”
Ian’s departure was announced in January, in the same month The Scotsman marked its bicentenary.
In his new role, which he begins on Tuesday, Edinburgh-born Frank will also work in collaboration with editors of JP’s 28 Scottish weekly titles, as well as ensuring growth of the i newspaper in Scotland.
Frank began his career as a reporter with the Carrick Gazette in Girvan, later moving to Dundee Press Agency in 1998.
He joined The Scotsman in 2000 and held numerous roles with the title including Edinburgh reporter, specialist reporter, forward planning editor and news editor before moving into senior editorial positions.
Editor-in-Chief Jeremy Clifford said: “I am pleased to see Frank emerge from what was a very strong field of candidates – both internal and external – reflecting the quality of talent we have in Johnston Press and in our industry. This was a tough and rigorous selection process and I would like to thank all candidates who figured so strongly during the interviews.
“Frank will lead the three titles through what is certain to be one of the most important times in Scotland’s history and will be in charge of positioning The Scotsman to be the leading media voice during this period.
“He has set out a first class vision to develop The Scotsman in print, build its brand, develop the team and lead the digital transformation of the business.”
Johnston Press chief executive Ashley Highfield added: “Frank’s appointment demonstrates JP’s commitment to see the development of The Scotsman brand in all formats and, along with the i newspaper and our Scottish local titles, continue to grow our market share in Scotland.”