The 24 year-old has joined the Parkhead club on a year-long loan, with the Hoops holding an option to make the deal permanent.
Mubarak had hoped to be signed in time to play in the Champions League Play-off matches against Nk Maribor.
But, his registration could not be concluded until a work permit was issued.
Due to the fact Wakaso has not played in at least 75% of Ghana's full international in the last two years, the application had to go to appeal, which was heard by a specially-convened panel.
Wakaso has been waiting in Paris, where he underwent a medical at the start of the week under the supervision of Celtic head physio, Tim Williamson, until the final piece of paperwork was received.
Now he has finally arrived in Glasgow, but found Celtic Park a subdued place today after last night's exit from the Champions League at the hands of Maribor.
Wakaso - who previously played for Villarreal and Espanyol in Spain before moving to Russia last summer - will now be added to Ronny Deila's squad which will go into Friday's draw for the Group Stage of the Europa League.
The Hoops boss is hoping to add at least one other player before the transfer window closes on Monday.
But, despite agreeing a transfer fee with Sporting Gijon for Stefan Scepovic, the Serbian striker today appeared to be keeping his options option.
Dutch side, PSV Eindhoven could be ready to make their move for him and Scepovic said: "Celtic? I would be happy to go there, for sure.
"But PSV is also big club and I must admit that there are even more options.
"I think that soon everything will be sorted out."