Gianni Bismark Guigou Martínez (born 22 February 1975 in Nueva Palmira) is a Uruguayan former footballer who played as a midfielder.
He started his career in Nacional, where he played from 1994 to 2000, winning the Uruguayan league titles of 1998 and 2000.
Guigou left for Siena on loan in summer 2003 and sold to Fiorentina in July 2004 for a nominal fee of €516.
[2] In June 2006 he left for newly relegated Serie B side Treviso as part of Massimo Gobbi and Reginaldo's deal.
[3] After the club was excluded from professional football in 2009, he was released for free by the federation and later joined Nacional, back in Uruguay.