The chief of staff will support the mayor in his day-to-day leadership of the city and ease the workload of existing over-worked staff members in the mayor's office.
He said his staff were well aware they were not allowed to show any political bias so would not be helping with his campaign in any way.
He met Perry for the first time when he interviewed her last week before offering her the job.
The new role is to be funded from existing budget's from the mayor's office. In 2017, the council confirmed the budget for the mayor's team was $390,000. Council would not provide the salary for the chief of staff.
King set up his office in early 2017 with only an executive assistant and mayoral adviser - one less person than previous mayor Julie Hardaker's team of three - chief of staff, executive assistant and policy and community coordinator. She also had approval for a press secretary but never filled the role.
Hamilton city councillor and mayoral candidate Angela O'Leary was critical of the move.
While she supported a mayor having a chief of staff, she thought the timing was all wrong.
"He needs help because he has to campaign and has found himself quite busy. But of course all of us incumbents like myself have to campaign and also carry on doing what is more than a full-time job as well."
Paula Southgate, who is also a city councillor and standing for mayor, said she was only first made aware that he was looking to fill the role when elected members were notified in a public excluded part of a council meeting the day before the announcement.
She said it raised a lot of questions including the cost and what the value to ratepayers was and thought he could have waited until after the elections before appointing someone.
Councillor Rob Pascoe commented on Facebook that it was "curious timing".
"Checks need to be taken that this additional cost to the ratepayer is not used to pay for his re-election campaign, an activity Mayor King started back in December last year."
However King said the self-funded billboards erected around the city, of which there have been five so far, promoted a position of council message not his personal position.