The Ghana international was delighted to join the Magpies and will now be looking for a run in the team after two years of frustration at Everton, Bournemouth and Malaga.
After signing for United, Atsu said: “I’m very happy to be at Newcastle,” said Atsu.
“It’s a very big club.
“They have good facilities and I think Newcastle have one of the best coaches in the world.
“St James’ Park is a fantastic stadium with 50,000 fans; the fans here really love football so much and I can’t wait to play at this stadium in front of the fans.”
And Rafa Benitez was also pleased to bring in a quality addition.
After luring him to Tyneside, he said: “I agreed with our fans that we needed to bring in another winger, so I am very happy to welcome Christian to the Club.
“He has good ability and pace in the wide areas and also has good experience of English football.
“He has a different style of play to the other players we have at the moment and that will be important for the squad.”
A United statement read: “The 24-year-old arrives from Chelsea on loan until the end of the season, with an option for the Magpies to make the move permanent next summer.”
NEWCASTLE 2 BRIGHTON 0 (Lascelles, Shelvey)
Sels, Anita (72' Gamez), Mbemba, Lascelles, Dummett, Ritchie, Hayden, Shelvey, Gouffran (88' Yedlin), Diame (81' Colback), Perez
Subs: Clark, Hanley, Darlow, Armstrong
(LC) NEWCASTLE 2 CHELTENHAM 0 (Perez 2)
Darlow, Sterry, Lascelles, Hanley, Gamez, Aarons (24' Gouffran), Shelvey, Colback, Perez, Diame, Mitrovic (38' Gayle)
Subs: Dummett, Hayden, Mbemba, Sels
BRISTOL CITY 0 NEWCASTLE 1 (Gayle)
Sels, Anita, Mbemba, Lascelles, Clark, Ritchie, Hayden (87' Shelvey), Colback, Gouffran, Diame (63' Perez), Gayle (88' Aarons)
Subs: Dummett, Hanley, Darlow, Sterry
NEWCASTLE 4 READING 1 (Hayden, Ritchie (P), Gayle 2)
Sels, Anita, Mbemba, Clark, Dummett, Hayden, Shelvey, Ritchie (90' Aarons), Perez (76' Lascelles), Gouffran (84' Colback), Gayle
Subs: Hanley, Janmaat, Darlow, Armstrong
NEWCASTLE 1 HUDDERSFIELD 2 (Gayle)
Sels, Janmaat (83' Armstrong), Mbemba, Lascelles, Dummett, Anita, Hayden, Shelvey, Aarons (45' Ritchie), Diame (75' Perez), Gayle
Subs: Clark, Colback, Darlow, Gamez
FULHAM 1 NEWCASTLE 0
Sels; Janmaat, Lascelles, Hanley, Dummett; Hayden (Shelvey 77), Colback (Aarons 61); Ritchie, Perez (Armstrong 70), Anita; Gayle.
Subs Mbemba, Darlow, Jesus Gamez, Sterry.
NEWCASTLE 3 VITESSE ARNHEM 2 (Leerdam (og), Gayle, Colback)
Sels; Janmaat (Sterry, 74), Hanley (Gamez, 62), Lascelles, Dummett; Hayden (Saivet, 74), Colback (Shelvey, 62); Anita (Mitrovic, 74), Perez (Armstrong, 62), Ritchie (Aarons, 62); Gayle (Gouffran, 74). Subs not: Darlow, Tiote, Thauvin.
SOUTHEND UTD 0 NEWCASTLE 2 (Anita, Gouffran)
Darlow; Janmaat (Sterry 63), Mbemba (Hanley 63), Lascelles, Dummett; Hayden (Colback 63), Shelvey (Saivet 73); Anita (Thauvin 78), Perez (Mitrovic 73), Aarons (Gouffran 63); Gayle (Armstrong 63).
Sub not used: Sels.
SPORTING LOKEREN 0 NEWCASTLE 4 (Perez 2, Perez, Janmaat, Shelvey)
Sels (Darlow 72); Sterry (Gouffran 63), Mbemba (Saivet 72), Lascelles (Dummett 63), Anita (Gamez 46); Hayden (Shelvey 46), Colback (Tiote 72); Janmaat, Perez (Mitrovic 46), Aarons (Thauvin 63), Gayle (Armstrong 63).
Subs not used: None.
DONCASTER ROVERS 2 NEWCASTLE UTD 2 (Hayden, Perez)
Sels, Janmaat (Sterry, 45), Mbemba (Saivet, 65), Lascelles (Dummett, 45), Colback (Hayden, 45), Anita (Gamez, 45), Ritchie (Gouffran, 45), Aarons (Perez, 45), Shelvey (Wijnaldum, 79), Mitrovic (Gayle, 45), Armstrong (Thauvin, 60).
BOHEMIANS 0 NEWCASTLE 6 (Ritchie, Mitrovic, Gayle, Thauvin, Aarons, Wijnaldum)
Sels, Anita, Lascelles, Mbemba, Sterry, Aarons, Colback, Gouffran, Ritchie, Saivet, Mitrovic.
Subs: Darlow, Gamez, Dummett, Wijnaldum, Shelvey, Hayden, Perez, Gayle, Janmaat, Tiote, Thauvin.
CHAMPIONSHIP TABLE (Top 10)
1 Huddersfield Town 13
2 Fulham 11
3 Barnsley 9
4 Newcastle United 9
5 Queens Park Rangers 9
6 Bristol City 9
7 Nottingham Forest 9
8 Brighton and Hove Albion 8
9 Wolverhampton Wanderers 8
10 Birmingham City 8