The forward made 12 appearances for Saracens during a spell at Allianz Park earlier in the campaign and he became a popular figure among fans and players.
He returned to Cornish Pirates for a short stint but has agreed another switch to Saracens until the end of 2018-19.
Saracens have been hit by an injury to England international Mako Vunipola, who is expected to be sidelined for 10 weeks, and Judge will deputise.
Judge told the club's official website: "It's really great to be back. My first spell at the club was an unforgettable experience which I loved and I'm relishing the opportunity to pull on a Sarries jersey again.
The support I had here was humbling and I'm really looking forward to working hard and getting stuck in.
"I'd also like to take this opportunity to say a massive thank you to everyone at Cornish Pirates for everything they've done for me during my time at the club.
"The coaches Gav, Paves and Morgs alongside our support team have invested a great deal of time and energy into helping me develop and for that I'm hugely grateful. Likewise, I'd like to thank my teammates for many great memories both on and off the pitch.
"Finally, thank you to all of the fans who have been amazing from day one."
Judge's performances for Saracens earlier in the term have earned him a permanent switch to Bath from 2019-20.