The Argentinian struggled to get into the first team at the Donbass Arena last season following a move from his native Velez Sarsfield in July 2013, although he did manage to find the net six times from five starts, and had been linked with a move to Newcastle for most of the summer.
That has now been completed by the Magpies, who have the option to buy the 23-year-old at the end of the season.
The Magpies will have an option to buy the 23-year-old Argentine striker at the end of the campaign.
He has already joined up with the Magpies' squad in Germany as they take part in this weekend's Schalke 04 Cup.
"I am very pleased to sign for Newcastle United," said Ferreyra.
"I like the Premier League and when I knew that Newcastle were interested in me, it was a very easy decision to make.
"I spoke to my friend Fabricio Coloccini, and when he told me about the club, I didn't need to think twice."
Alan Pardew was thrilled with his new signing: "Facundo is someone we know on a number of levels, including his friendship with Fabricio (Coloccini), and we think he could be a big success here at Newcastle.
"This is a player who has played at the top level and is highly-regarded in Argentina. He has tremendous potential and hopefully he can realise that here at Newcastle United."
- Sports & Recreation
- Newcastle United
- the Magpies
- Fabricio Coloccini