Six of the eight state unions had signed a letter calling for McLennan to resign on Friday and he was finally voted out in one of a series of emergency board meetings held over the weekend.
McLennan, a successful businessman who had overseen the hiring of Eddie Jones to run the ill-fated World Cup campaign, immediately resigned from the board.
Herbert, who played 67 tests for Australia in the golden era around the turn of the century when the Wallabies won the World Cup for the second time, said he would continue to drive the structural reforms of the struggling game.
"It has never been more important for the Rugby Australia board to come together and execute the reform we absolutely need for an aligned high-performance system and to deliver on the commitments we have made, including to invest in community and women's rugby," the 49-year-old said in a RA news release.
The hiring of Jones and sacking of Dave Rennie in January was driven through by McLennan but backfired spectacularly when the former England coach selected an inexperienced squad for the World Cup.
Jones resigned at the end of October saying the structural changes to the game required to make the Wallabies competitive were unlikely to be realised in the short-term.
Chief executive Phil Waugh launched a plan for structural reforms in August and last week announced that the New South Wales Rugby Union would be the first to hand over their high performance programme to centralised RA control.
Other states, most notably the powerful Queensland and Australian Capital Territory (ACT) unions, had qualms about the wholesale takeover of their high performance units, which includes their Super Rugby franchises.
Both of those unions were signatories to the letter and McLennan had suggested that the restructuring of the game was behind the attempt to oust him.
Herbert, a Queenslander, said that was not the case.
"Australia will host the British and Irish Lions Tour in 2025, the Men's 2027 Rugby World Cup and the Women's 2029 Rugby World Cup and the 2032 Olympic Games," he added.
"The reform we progress now will underpin the competitiveness of our national teams, as well as building deeper engagement with the rugby community and fans everywhere.
"We note that the different member unions are not opposing Rugby Australia's centralisation proposals and remain committed to supporting high performance alignment."
RA paid tribute to McLennan's role in helping the game get through the COVID pandemic, which brought the governing body close to bankruptcy, and in securing the hosting of the men's and women's World Cups.
