The New Zealand filmmaker became involved in the legal battle to free the men who always maintained they were innocent.
Known as the West Memphis Three, the men - Damien Echols, Jason Baldwin and Jessie Misskelley - were found guilty in 1994 of killing three Cub Scouts in Arkansas in 1993.
The documentary, West of Memphis, is produced by Echols and his wife Lorri Davis, in collaboration with Jackson and his wife Fran Walsh.
After a seven-year legal battle, which Jackson and Walsh helped fund, the three men were released from prison in August.
The trio accepted a bargain deal that allows them to assert their innocence while acknowledging that prosecutors have enough evidence to convict them.
They were released with 10-year suspended sentences.
West of Memphis is written and directed by Oscar-nominated filmmaker Amy Berg and features original music by Nick Cave and Warren Ellis.
Echols, Baldwin and Misskelley were teenagers at the time they were arrested for the murders.
Echols was sentenced to death, while Baldwin and Misskelley received life sentences.
They each spent 18 years in prison before they were released.
Jackson and Walsh are among a number of high profile celebrities who have supported their bid for freedom.
At least three other films have been made about the case, and a number of books written.
