Clint Eastwood & Wife Dina -- Separated

Clint Eastwood's marriage has gone from the good, the bad, to the ugly ... the 83-year-old actor has separated from his wife of 17 years.

48-year-old Dina Eastwood -- Clint's second wife -- said the two remain close but have been living apart now for some time.

Dina and Clint were married in 1996 and have one daughter together, 16-year-old Morgan. Clint has seven other children from previous relationships.

TMZ broke the story ... Clint and Dina's marriage has been on the rocks for a long time, and Dina was so upset about her crumbling relationship that she entered rehab for depression and anxiety.