Monsignor Kevin McAuliffe was convicted of taking $650,000 (Â£424,000) away from his congregation to support his gambling habit.
Defence lawyers asked for probation so McAuliffe could keep practising as a priest and get addiction counselling.
But the judge added four months to the sentence that prosecutors pushed for.
Prosecutors argued McAuliffe was able to hide his activities because he was a signatory to the financial statements of the Las Vegas diocese and the archdiocese in San Francisco.
In his defence, his lawyer argued that McAuliffe had begun returning the money to his parish since May and had paid back $13,420 to date.
In October, McAuliffe pleaded guilty to three counts of mail fraud and falsifying documents sent to the archdiocese in 2008, 2009 and 2010. He was also removed from his Las Vegas parish and stripped of duties to the diocese.
Supporters sobbed in the courtroom as the judge told McAuliffe he had abused his position of trust within the church community.
McAuliffe offered a remorseful apology, the Associated Press reported, saying he felt "guilt, shame and self-loathing''.
He accepted his loss of authority within the Church and asked for leniency so he could make restitution.
He could have received up to 60 years in prison.
A Roman Catholic priest from north-west Las Vegas has been sentenced to three years and one month in a US prison for using parish funds for gambling.