Hélio Castroneves (born Hélio Castro Neves on May 10, 1975 in São Paulo, Brazil) is one of the top drivers in North American open-wheel racing, first in the CART series and now in the IndyCar Series. He won the Indianapolis 500 in both 2001 and 2002, becoming the fifth driver to do so in consecutive years, and finished second to teammate and countryman Gil de Ferran in 2003. He is a two-time winner of the pole position for the race, including 2007.

After being occasionally misidentified by U.S. media as "Helio Neves" he at first changed the spelling to Helio Castro-Neves and then to the current spelling. He has one sister, Katiucia. After showing potential but lacking reliability while with the Bettenhausen and Hogan teams, Helio was signed by Penske Racing in CART in 2000 following the death of Greg Moore who was killed during the last race of the 1999 season in California. Moore had signed on with Penske but never had the opportunity to race with the team. Castroneves immediately became a regular front-runner. He switched with the team to the rival IRL for 2002, and has remained there ever since, now teamed with American Sam Hornish Jr.

Racing fans have given Castroneves the nickname "Spider-Man" because of the form of victory celebration he introduced, in which he climbs the track-side debris fence, a practice since adopted by NASCAR driver Tony Stewart in the 2005 Nextel Cup season.