Andrew Dixon, now an arts consultant, is the bid advisor to Hull, which is competing with Dundee, as well as Leicester and Swansea for the prestigious title. The winner is to be announced in November.
Eleven towns and cities were in contention for the title, including Aberdeen, before the shortlist was announced in June. Mr Dixon helped steer the Hull bid to the final four.
The public post is Mr Dixon's first since he left Creative Scotland last December, when he resigned from his post with a £60,000 payoff as controversy engulfed Creative Scotland.
He left two months after a devastating letter of criticism - signed by more than 400 of the nation's artists, writers, playwrights, musicians and composers - was sent to the arts organisation criticising its policies and language.
Mr Dixon's successor, Janet Archer, is overseeing a series of reforms to the body, which distributes £100 million in Government and National Lottery funds a year.
At the time, the body said that Mr Dixon was standing down to make way for a new leader to steer the organisation through the coming "period of change".
Mr Dixon is helping to guide the Hull bid, which will submit its final documents to the Department of Culture, Media and Sport at the end of September.
Hull, which has had backing from the playwright John Godber, filmmaker Mark Herman and artist Richard Wilson, will vie with Dundee, which has had support from the V&A in Dundee, Billy Connolly, Emeli Sande and Lorraine Kelly, among others.
The UK City of Culture independent advisory panel, chaired by Brookside creator Phil Redmond, assesses all the bids and recommends the final winner to ministers.
Mr Dixon was unavailable for comment. However, he has previously told a Hull newspaper: "The Hull bid is serious.
"It's not about celebrity endorsement, it's about tackling some of the economic problems we have in the city and then using culture to change that and really change people's lives."
He said Hull had a "compelling moral case" to make it on to the shortlist.
He said: "There is some strong competition from cities such as Leicester, Dundee and Plymouth - but I believe Hull has what it takes to be up there with the favourites."
He added: "Making the shortlist is crucial. To use a footballing analogy, it's like working all season to make it to the playoffs.
"Once you're there, it's all about showing who's got the strength of character and the ability to come out on top."
Before he moved to become the first chief executive of Creative Scotland, Mr Dixon had 30 years of working in the arts and creative industries.
He was chief executive of the NewcastleGateshead Initiative for five years, chief executive of Northern Arts and on the national executive of Arts Council England.
As chief executive of Northern Arts, advocated for and helped find funding for large projects such as the Baltic, the Angel of the North and The Sage in Gateshead.
When he resigned from Creative Scotland, he said: "I have been disappointed, given my track record, not to gain the respect and support of some of the more established voices in Scottish culture."