The Austrian defender has lavished praise on the French winger and Philipp Lahm ahead of Bayern Munich's Champions League clash with the Spanish giants.
Ribery has come under fire for a dip in form during recent weeks, with former Bayern goalkeeper Oliver Kahn claiming the Frenchman was struggling to shake off the disappointment of losing out on the Ballon d'Or in January.
The 31-year-old was back on the scoresheet as he inspired his side to a 5-2 win over Werder Bremen during the weekend, and Alaba is confident the Frenchman will be key against Real Madrid on Tuesday.
"We are aware it is not easy against Real," the defender told reporters. "They have great players but we will not focus on our opponent, we will concentrate on our strengths. Franck Ribery showed at the weekend what a fantastic player he is. He is a great personality."
Alaba also praised club captain Philipp Lahm, claiming he has never seen the Germany international deliver a below-par performance, irrespective of which position he was playing in.
"Lahm is always playing at the top level, I have never seen him playing poorly," he said. "We want to reach the final in Lisbon. It's our dream to go through to the final. My role depends on the opponent. I can move into the center, I can stay on the wing. It depends on what the coach tells us.
"Last year in the Champions League against Barcelona we noticed what the fans are capable of and we need our fans tomorrow again. They will push us to attack."