Emmy Award-winning actor Harry Morgan -- who played Colonel Potter on the series M*A*S*H -- died this morning in his L.A. home ... this according to the actor's son.

His son Charles told the NY Times ... Morgan was recently treated for pneumonia -- thought it's unclear if that was a cause of death.

Morgan had an illustrious TV career -- also starring in "Dragnet," "Pete and Gladys," "December Bridge," and "Hec Ramsey."

Morgan is survived by his wife Barbara, three son's from his previous marriage, and eight grandchildren. He was 96.