The 19-year-old has joined on a short-term deal which will keep him at the Dons until January 1. He is eligible to face MK Dons in the FA Cup.
Ardley has also brought in former Kettering Town midfielder Ryan Hervel, who has signed on a short-term deal as he has been without a club.
"We have a busy period coming up and we are in a dogfight. Good players like this do not become available too often so we have to utilise them," Ardley told the club's official website.
"We have had rave reviews about Paul. I have had contacts ringing me up and telling me how good a player he is and I have spoken to Ian Hendon, his U21s manager at West Ham, and he believes Paul will be ideal for us. He is a big, strong lad, who links the play up well.
"Ryan was at Kettering at the start of the season, but he had to leave due to financial problems at the club. With us having so many loan players, it was a good opportunity to sign Ryan, who was without a club.
"I watched Ryan at the Bailey Elite Academy and he has very good qualities, which can help us out. It is also a chance for Ryan to prove himself before January."