Jonathan Norman, 31, was convicted earlier this year of stalking the director after being caught at Spielberg's estate with handcuffs and duct tape last summer.
The hearing in Santa Monica, California, was told he planned to rape the director in front of his wife.
Spielberg, reading a prepared statement in court yesterday, asked Judge Steven Suzukawa to give the maximum sentence. He told him: "I place myself in your hands.''
The director, who was in Ireland filming Saving Private Ryan when Norman was caught, added: "The prospect he might have another opportunity to carry out his threats is beyond frightening to me.
"Had I not been out of town on the first of July, I genuinely, in my heart of hearts, believe I would have been raped or maimed or killed, and the same could have happened to my wife and kids."
Norman, who was flanked by two sheriff's deputies when Spielberg read his statement, stared at the director. But Spielberg avoided his would- be assailant's gaze by looking directly at his notes.