The 60-year-old, who replaces Steve Brown after he announced his surprise resignation at the end of 2018, will join the RFU after more than five years at the helm of British Athletics, and is tasked with addressing the financial turmoil that has hampered the governing body over the last 12 months.
Sweeney was among a select few who underwent final interviews last week, and once a date has been confirmed for him to take up the vacancy, Nigel Melville will return to his role as professional rugby director, having held the position of interim CEO following Brown’s resignation.
“I leave behind a very strong British Olympic Association, both financially and in readiness for Tokyo 2020,” Sweeney said. “This is the only opportunity that I would have left the BOA for. From the grassroots game to our England teams, rugby’s values and opportunities are very special. I am passionate about the game and it is an honour to be joining the RFU team."
Sweeney does hold a history in rugby union, having played at amateur level for Aberdeenshire and Rosslyn Park.
RFU Chairman Andy Cosslett added: "We are delighted to announce Bill’s appointment as CEO. He brings a rare combination of experience from the worlds of blue chip business and elite sport and has a tremendous track record in both. His passion for the game is deep rooted and this will stand him in very good stead."
Sweeney was at the helm of the BOA for their most successful ever Olympics at Rio 2016 as Great Britain finished runner-up in the medal table, while he has also held senior roles in major sportswear brands Adidas and Puma, as well as corporate management experience with Shell, Mars and Unilever.
The CEO role at the RFU is one of the most lucrative positions in world sport, although Brown’s salary was known to be less than the £710,000-a-year paid to his predecessor Ian Ritchie in 2017, which made him the highest-paid sporting chief executive in the country.