McGoldrick, 25, has joined Town on loan from Nottingham Forest with a view to a permanent move.
He told the club's official website: "It feels great to be an Ipswich Town player and everyone knows it's a big club.
"The chance to come and play for a club of Ipswich's size and under a manager like Mick McCarthy was something that I just couldn't turn down and I'm delighted to be here.
"I'm glad that the deal is finally done and I'm looking forward to getting to know all the lads and getting my Ipswich career started.
"I'd known about Mick's interest for a while but then I went back to Forest from my loan spell at Coventry and I thought I would be staying there.
"Then I got the call to come down to Ipswich and the next day I had signed, passed my medical and was training with the boys. It's been a crazy 24 hours but I'm just happy that it's all done now."
McLean, 29, has moved to Ipswich on loan from Hull City for the remainder of the season.
He said: "I'm delighted to be joining such a good club and hopefully I can help fire Ipswich up the table.
"I'm eager to be playing games and I'm raring to go. It's a loan until the end of the season originally but you never know what's going to happen in the future. If everything goes well for all parties then I'm sure me and the gaffer will look at it."