Seagal - a Russian citizen who was named in August as the Kremlin's newest special envoy to the United States - has faced more than half a dozen allegations of sexual assault, including rape, over several decades.
The Spacey case, involving an adult male, was presented to Los Angeles prosecutors in April and had been under review.
However, prosecutors said the case could not be taken forward because the year of the alleged crime falls outside of California's statute of limitations.
Spacey, 59, is being investigated in the United Kingdom for six sexual assault claims over 22 years.
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Prosecutors also declined to prosecute alleged sex crimes against the actors Steven Seagal and Anthony Anderson.
The case for the action-movie star Seagal, who was accused of assaulting an 18-year-old acquaintance in 1993, was also abandoned on the same grounds.
Spacey became embroiled in controversy in 2017 when actor Anthony Rapp accused him of trying to seduce him in 1986 when Rapp was 14. The victim was 18 years old at the time.
Police in London are investigating six criminal cases against him.
The two-time Oscar victor has been accused of sexual misconduct by at least 15 men, with alleged incidents spanning his decades in film and on the stage. The accusation was made less than two weeks after Anderson, 48, received his fourth Emmy nomination for outstanding lead actor in a comedy series for "Black-ish". Spacey, 59, stated that he did not remember the alleged incident, but apologized for what "would have been deeply inappropriate drunken behavior". His film Billionaire Boys Club flopped, he was sacked from Netflix drama House Of Cards and erased from Sir Ridley Scott's All The Money In The World.