The former Bournemouth boss succeeds Steve Bruce, who left the Premier League club by "mutual consent" on October 20.
Emery said he was grateful for being considered for the Newcastle job but was “even more grateful” for being able to continue with the Spanish club.
Manchester City are now five points off the top after Pep Guardiola's 10 men were beaten 2-0 by Crystal Palace at the Etihad.
In an official release, Steve Bruce said: "I am grateful to everyone connected with Newcastle United for the opportunity to manage this unique football club."
AS Roma is currently at the fourth position in Serie A standings with 15 points from seven games.
Many activists have alleged that the MBS and Saudi Arabia are using this to cleanse their reputation globally and to shift the discussion from the lack of democracy in the country.
Hatice Cengiz said the £300 million ($408 million) takeover deal was "heartbreaking" for her and she was "very disappointed".
Brazilian midfielder Raphinha gave Leeds a 13th-minute lead when his cross was cleverly dummied by Rodrigo as it curled past Newcastle goalkeeper Karl Darlow.
Tottenham Hotspur has condemned the racial abuse directed towards its defender Davinson Sanchez following a EPL match against Newcastle United.
Willock, a 79th-minute substitute, smashed a close-range finish into the net off the crossbar six minutes later.
Sterling's 31st minute goal ensured Manchester City took advantage of second-placed Manchester United's costly draw with Burnley.
The second half began as quietly as the first, with only a deflected Hazard shot raising excitement levels among the crowd above the soporific.
Conte's side play Newcastle United in the 1230 GMT kick-off at Stamford Bridge on Saturday, having beaten Swansea City 1-0 on Wednesday.
Mourinho admitted he felt emotional to see Zlatan Ibrahimovic return from his career-threatening knee ligament operation.
Pogba is in a different class declared Jose Mourinho after his performance in Manchester United victory over Newcastle.