Sheppard, media relations manager at Westminster City Council, will take the role in the next couple of weeks as part of a swap with current Harrow comms head Lindsay Coulson.
The head of comms for Harrow is employed by Westco, the company that trades out Westminster City Council's services and oversees Harrow’s comms set-up.
The switch follows Tory councillor Susan Hall being made council leader last month after the Conservatives and Labour united to vote out the minority Independent Labour administration.
It is understood that Sheppard’s previous work with Hall – he was head of news at the council between 2007 and 2009 – was a key factor in the move.
The strength of Sheppard's media relations background, including involvement with the comms around the 2011 eviction of travellers from Dale Farm, is thought to have informed the decision.
Sheppard told PRWeek that he had "particularly enjoyed his first stint at Harrow" and was "privileged to be asked back a second time".
He steps in after nearly three years in the role for Coulson and will lead on the newly launched council campaign "Cleaner, safer, fairer Harrow".
This reflects Hall's comment after her election as council leader, when she said: "The reality is I want the Conservative vision: a cleaner, safer and fairer Harrow."
In the election, which followed the ousting of Independent Labour, Hall beat Labour group leader David Perry by 31 votes to 24, with five abstentions.
Labour was initially voted into power at Harrow Council in 2010, with 34 councillors to the Conservatives' 27.