Efthimis Bakatsias (Greek: Ευθύμης Μπακατσιάς, Greek pronunciation: [ef'θimis bakat͡s'ças]; January 14, 1968) is a retired Greek professional basketball player. Born in in Athens, he played professionally in the Greek Basket League and represented Greece at senior level.
He started his career at AO Pagrati BC. He played for Olympiakos BC from 1993 to 1998 winning four Greek Championships (1994, 1995, 1996, 1997) and two Greek Cups (1994, 1997). In 1997 with Olympiacos Efthimis Bakatsias won the Euroleague as well as both of the Greek championships making him winner of the Triple Crown in Basketball. He also participated at two Euroleague finals (1994 Tel Aviv, 1995 Saragoza) and at the 1997 McDonald's Championship final.
He was a member of the Greek National Squad that won the 4th place in the 1994 FIBA World Championship. Totally he appeared in 84 games for Greece averaging 4.8 points per game.