Tarso Fernando Herz Genro (born March 6, 1947 in São Borja, Rio Grande do Sul) is a Brazilian politician, and a member of the Workers' Party (Partido dos Trabalhadores – PT). As a result of the Mensalão scandal, Genro served the remainder of José Genoíno's term as party president in 2005. Ricardo Berzoini was elected to the post later that year.
Following his service as interim president, Genro was a top political adviser to Luiz Inácio Lula da Silva, former President of Brazil (2006–2010), during the contentious, but quite successful, 2006 Presidential campaign. On 16 March 2007, he became the new Minister of Justice in Lula's cabinet.
Genro is the former mayor of Porto Alegre, the capital city of Rio Grande do Sul, and was a candidate for the state's governorship in 2010. Since January 1, 2011, he is the Governor of Rio Grande do Sul.