The actress, who plays Michael Scott's love interest Holly Flax, told Access Hollywood that she had finished filming weeks before Carell's exit.
"I'm sure [Holly and Michael's relationship is] factored in there, but I will say that I left the show before he did," she revealed. "He's actually filming his last episode right now."
She added that the sadness on-set has been "quite palpable" in the days leading up to Carell's departure.
"As a fan of Steve Carell, I'm happy because he's going to go make movies and he'll get to spend time with his family more," she said. "But it's weird when these huge characters on TV leave."
Ryan also denied having any knowledge of what direction the show will take in the future.
"It's such a good show, especially him," she suggested. "I don't know what they're going to do without him. The way he portrays that character is just so perfect. It's so on the dot."
The Office airs on Thursdays at 9/8c on NBC.