A Whitehall source has revealed the 58-year-old will receive the gong in the New Year Honours list on Thursday.
The election guru, who has been dubbed the "Wizard of Oz", also advised the National Party - coming under fire for his dirty tactics as an adviser for Don Brash in his unsuccessful attempt to oust Helen Clarke in 2005. He was also part of the team who advised John Key in his 2008 election victory, although his involvement then was kept under wraps. Helen Clark said at the time there were suspicions about the strategists used by the National Party because it wasn't honest about them.
Mr Crosby started working for Mr Cameron in 2013 and is credited with masterminding the Conservative party's first outright win for more than 30 years in May. Previously he had helped Boris Johnson become mayor of London.
But he became embroiled in a row over his links to the tobacco industry. He was forced to deny playing any part in the Government's decision to shelve plans for cigarette plain packaging when it emerged his lobbying consultancy CTF had been working for tobacco manufacturer Philip Morris.
Britain's Labour Party also highlighted his tax arrangements after he was linked to a network of offshore companies.
Mr Cameron has been accused of using the honours system to reward friends, political allies and donors.
Labour MP John Mann condemned the award for Mr Crosby, saying it degraded the honours system and was "an insult to the country's heroes".
Alexandra Runswick, the director of Unlock Democracy, which campaigns for political reform, said the honours system was supposed to be about rewarding dedicated public service.
"David Cameron is using it to reward a lobbyist and political consultant who helped get him elected demeans the honours system and undermines trust in politics."
Since 2002 Mr Crosby and his business partner Mark Textor have been advisers for more than 250 political campaigns in 57 countries.
