Magpies owner Mike Ashley made the decision to dismiss Hughton, despite the club lying a solid 11th in the Premier League table in their first season back in the top flight.
Martin Jol and Alan Pardew are among the frontrunners to take over at St James' Park, and Nolan admits the move has come as a major surprise to him and his team-mates.
In shock: Magpies skipper Nolan did not expect Hughton to be axed
He said: 'We are all upset that Chris is going. He helped a lot of the lads here with their careers when he was a coach and then as manager.
'We will never forget our promotion from the Championship last season and we have to do what he told us. Stick together, make sure we keep the unity Chris has built up and get through this difficult period.
'It goes without saying we were shocked by the announcement.'
All over: Hughton is no longer Newcastle manager
Former Bolton midfielder Nolan also paid tribute to how Hughton conducted himself after being informed of his fate, revealing that he had wished the players well for the remainder of the campaign.
'Chris was gutted about what had happened. You could see that,' Nolan continued. 'But it said so much about him that, even though he was obviously disappointed to be going, he was still telling me and Joey (Barton) that we had to make sure we had a good season.
'There was such dignity about the way he left, which is how he conducted himself while he was the manager.'
Toon turmoil: Jol and Pardew in the frame after Newcastle sack Hughton Did Hughton deserve to be sacked by Newcastle? Who should replace him?Matt Lawton: Why would anyone want to work for Mike Ashley now?Hughton betrayal: Ashley the assassin leaves Newcastle fans bewildered Martin Jol available to replace Chris Hughton at Newcastle after resigning at AjaxLMA 'extremely disappointed' as axed Hughton wishes Newcastle wellNewcastle sack Chris Hughton and spark hunt for 'more experienced' managerNEWCASTLE UNITED FC