Nimoy, who died Feb. 27 at the age of 83, originated the role of Spock on the Star Trek TV series and several big-screen followups. Quinto has played the character in the two most recent movies.
"We were very, very close, and losing him was really difficult, obviously," Quinto told talk-show host Conan O'Brien. "But I feel so grateful that I knew him and that he was such an instrumental figure in my life and he lived a beautiful life and a full life, and, so, in the end, I think there was much more celebration of what he accomplished and how many lives he touched in the world. We will certainly miss him. He was an amazing man."
O'Brien said he first met Nimoy years ago when he was a writer on the animated program The Simpsons and Nimoy lent his voice to a cartoon version of himself. O'Brien went on to say how he encountered tons of celebrities through his work on the show, but few left him as awestruck as Nimoy did.
"I freaked out because he was such an indelible part of my childhood," O'Brien revealed.