Kinnear will have the job until owner Mike Ashley can sell the club.
Former England boss Terry Venables turned down the job yesterday.
Kinnear said: “I am very excited about the challenge in front of me at Newcastle United.
“Results have not been great of late but there is a lot of quality in the squad and I am very confident the players are capable of climbing the league table.
“Newcastle United is a great club. When I was in charge of Wimbledon I always remember the passion of the fans up there and how great a stadium St James’ Park is.
“It is a big challenge but one I am really looking forward to.”
