Actor Hudson Meek's death is being treated as an accident, and it doesn't appear substances played any role in the fall that took his life ... TMZ has learned.

Law enforcement sources tell us ... no foul play is suspected in Hudson's death -- and, cops are looking into this as an accident.

We're told there were no signs of drugs or alcohol ... and, cops do not believe they played any part in the accident.

As we told you ... Meek suffered blunt-force trauma injuries from a fall on December 19 in Vestavia Hills, Alabama.

Hudson was rushed to an area hospital ... but, sadly, he passed away two days later.

His mother wrote a message about her son to Facebook shortly after his passing ... mentioning all he accomplished and the people he impacted in the course of his short life. He will continue to make an impact too -- with his organs being donated to those in need.

Among his credits ... Meek appeared in "Baby Driver," "MacGyver," "Found," "The School Duel," "90 Minutes in Heaven," "Badanamu Stories," and many more projects.

Hudson was just 16 years old.