Hall, who operates as Sarah Hall Consulting, is one of three candidates to be president-elect for 2017 and then president for 2018 of the CIPR, of which Ingham is a member and former employee.
Ingham told attendees at the PRCA-hosted launch of the second volume of the book #FuturePRoof, which is edited by Hall, that he was in favour of her goal of better relations between the CIPR and PRCA.
"If you are a member of the CIPR, then so you know where I stand; vote for Sarah Hall," Ingham said.
He told PRWeek he had never made such an endorsement in previous elections.
Neither Sarah Hall's candidate statement on the CIPR website nor her accompanying video pitch contain any reference to the PRCA, although candidates in previous years have made similar pledges.
Ingham has previously been vocal in his criticism of the CIPR, in particular of its role in consulting with the NLA over a new license for PR firms wishing to share news clippings with clients.
CIPR presidential election voting begins on Monday and the winner should be announced by the end of the month. The 2016 president-elect, who becomes president next year, is Liquid MD Jason Mackenzie, who was elected unopposed after the other candidate was disqualified.