Pennell has enjoyed the best form of his career under Dean Ryan and has been a stand-out performer in a number of matches this season.
After coming through the Warriors academy, the full-back became a club centurion against Harlequins at the end of last season and is the longest-serving player at Sixways.
At 26-years-old, Pennell is a player in his prime and his new contract signals Warriors' commitment to ensuring the best players remain at the club as we continue to build for the future.
Director of Rugby Ryan said: "This announcement comes as a statement of our long-term intentions and illustrates that our top players are buying into the vision.
"Chris has had a huge impact on the team this season and I am delighted that he has chosen to be part of this club for years to come.
"Not only has he shown tremendous commitment on the field, but his desire to stay with the Warriors until at least 2017 clearly demonstrates a passion to succeed at the club in which he began his career.
"I know this news will be welcomed by his teammates, supporters and everyone associated with the Warriors."
Chief Executive Charles Cameron added: "Chris is having a fantastic season and clearly believes this club has an exciting future.
"We are building a side which is capable of long-term success and it is great Chris wants to be part of that."