The League One side come to Tyneside for a 3pm (GMT) kick-off on Saturday, 25th January and the final few tickets were snapped up on Friday morning.
Head coach Steve Bruce said: "It's a full house, which is quite remarkable - (fourth) round of the FA Cup and, with no disrespect to Oxford, we've got 52,000, which is quite unbelievable.
"I'll play as strong as I can and try and get into the next round. I said that from the moment I walked through the door. Who knows - can we go on and have a cup run? We've got a wonderful opportunity.
"The city and the supporters would like nothing more than a cup run; they haven't had it for years. Let's see if we can get past (Oxford) and be in the last 16. It'd be great."
As with the third round replay against Rochdale, tickets were available in advance of the game for £10 for adults and £5 concessions. Additionally, as a special incentive to enable more young supporters to attend the game, tickets for children aged 12 and under were, for a limited period of time and subject to availability, made available for just £1.
Please note that all supporters aged 12 and under must be accompanied by an adult. Supporters who already purchased tickets for those aged 12 and under before Thursday, 23rd January can take their valid junior match ticket to the club shop on Saturday, 25th January (matchday) and present it for a discount of £5 off all items.
Hospitality is still available from £150 per person. Please call 0191 201 8444 to book.
To purchase tickets for future matches, please visit book.nufc.co.uk, call 0344 372 1892 or visit the St. James' Park box office (Milburn Stand) in person.