Raúl Carlos Sanguineti[1] (Paraná, 2 February 1933 – Buenos Aires, 6 August 2000) was an Argentine chess Grandmaster.

He improved the next year, 1955, with an excellent tie for fourth place at the Argentine Championship at Buenos Aires, where he scored 12/19.

Next was the very strong Buenos Aires 1955 event, which featured star Grandmasters Borislav Ivkov, Svetozar Gligorić, Hermann Pilnik and László Szabó, and he could only make 7.5/17 for 13th.

For Moscow 1956, Sanguineti made his debut on the first reserve board, and played sensationally to win the gold medal with a score of 9/11.

At Mar del Plata 1957, he scored 10.5/17 for sixth in a high-class field which included world #3 Paul Keres, beating Soviet Grandmaster Alexander Kotov.

He scored 9.5/11 to win at São Paulo 1957, finishing ahead of perennial Argentine champion Miguel Najdorf.

Then at Santiago 1959, he defeated American star Robert James Fischer, a future World Champion, and tied for fourth with 7.5/12.

After a two-year break from top competition, he placed third at the 1962 Argentine Championship with 13.5/17, and tied for fourth at Mar del Plata 1962 with 8.5/15, behind visiting stars such as Lev Polugaevsky, Vasily Smyslov, and László Szabó.

In 1963, he won the Buenos Aires Club Argentino event with 9/11, and the next year, he was perfect at Punta del Este (Uruguay) to win there with 7/7.

With a 2600 performance generally denoting grandmaster standard, it seemed quite clear that Sanguineti deserved a promotion to the higher title, based upon his consistently strong results in good calibre events.

At Buenos Aires 1965, Sanguineti scored 6.5/11 to end fourth, and he won the 1965 Argentine Championship with an impressive 16/21.

Mar del Plata 1965 was again very strong, with Najdorf, Leonid Stein, and Yuri Averbakh in attendance, and Sanguineti could only manage eighth place with 8.5/15.

Sanguineti claimed his second Argentine Championship title in 1973 at Santa Fe with a dominant 13.5/18, two points clear of the field.

An unexpected break to his streak of good play was the 1975 Buenos Aires CA tournament, where he could manage only 4.5/11.

He claimed the tournament title at the Fortaleza Zonal 1975 with 13/17, 1.5 points ahead of runner-up, countryman Miguel Quinteros.