His wife said that his death was caused by the end stages of chronic obstructive pulmonary disease.
The actor, whose "Star Trek" character's "live long and prosper" catchphrase became iconic to generations of fans, also appeared as an older version of Spock, Spock Prime, in the recently rebooted "Star Trek" and "Star Trek Into Darkness" movies.
Nimoy was known as more than just Spock, however. He was an author, penning two autobiographies ("I Am Not Spock" and "I Am Spock"), a photographer who crusaded for better body image, a screenwriter, a director, a poet and a veteran of the U.S. Army.
He signed most of his tweets, including his final tweet on February 23, with LLAP: Live long and prosper.
Celebrities and fans also came out with memories of the actor, but none more powerful than Zachary Quinto, who played Spock along with Nimoy in the rebooted "Star Trek" film series: