10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
This season he has made 13 competitive appearances for Ulster, scoring two tries against Glasgow Warriors and Cardiff Blues..
Commenting on his new deal, Allen said: "Signing a senior contract with Ulster has been an ambition of mine ever since I joined the Academy, so I am delighted to have fulfilled that goal.
"I have enjoyed being part of the set-up and playing so many games this season. Ulster is my home province, it's where I grew up and it's where my friends and family live, so it means a great deal to wear the shirt.
"I look forward to helping Ulster be successful over the next two years."