Fabián Roncero Domínguez (born 19 October 1970 in Madrid) is a former long-distance runner from Spain.

His personal best of 59:52 minutes for the half marathon, set in 2001, lasted as a European record for fourteen years.

On grass, he was a four-time participant at the IAAF World Cross Country Championships, his best outing being tenth in the long race in 1998.

He won a bronze medal at the 2002 European Cross Country Championships, leading the Spanish men to the team title as well.

As of 2014, he remains the most recent European man to win the Rotterdam Marathon.