'Survivor' Contestant Semhar Tadesse -- I Admit It, I DROVE DRUNK

"Survivor" cast-off Semhar Tadesse just admitted in open court ... she was three sheets to the wind when police arrested her for DUI last October -- and now, she's ready to face the music.

TMZ broke the story ... cops pulled over 25-year-old Semhar after she ran a red light -- then arrested her on suspicion of drunk driving ... after she bombed a field sobriety test.

Semhar pled guilty today to misdemeanor DUI -- and was sentenced to 3 years probation. In addition, Semhar was ordered to attend an alcohol education program, and pay a $1,827 fine.