Liguori will join Discovery on 19 January. His latest position was president of entertainment for Fox.
As chief operating officer, Liguori will have oversight of areas such as marketing, production, corporate communications and technology.
As president of entertainment for Fox, Liguori was responsible for all programme development and marketing. Prior to that position, in 2005, Liguori was president and chief executive of News Corp's FX Networks.
He has also had spells in advertising at Ogilvy & Mather and Saatchi & Saatchi.
Last week, Discovery appointed Hollinger as head of its international TV arm, Discovery Networks International, replacing Greg Ricca.
It is not known whether Ricca has a job to go to outside Discovery, but he will remain with the company during what it labelled a "transition" period.
This article was first published on mediaweek.co.uk