'127 Hours' Amputee Aron Ralston -- Arrested on Suspicion of Domestic Violence

The real world inspiration for the Academy Award nominated movie "127 Hours" was arrested Saturday night in Denver on suspicion of domestic violence ... TMZ has learned.

Aron Ralston -- the man who made headlines in '03 after he ACTUALLY amputated his own forearm with a pocket knife when a boulder dislodged and trapped him inside a Utah canyon -- faces one count of assault and one count of "wrongs to minors" ... according to reports.

The movie based on his best-selling book was nominated for 6 Oscars -- including a Best Actor nom for James Franco who played Ralston.

Aron is currently being held in Denver County jail with no bail and is scheduled to appear in front of a judge tomorrow.

8:10 AM PST -- According to the police report ... Ralston told cops his girlfriend punched him twice in the back of the head after he pushed her during an argument about his son with another woman.

The report also says the couple's 8 month old son was present at the time of the assault.