Born in
São Paulo, Guilherme Lopes was a
Grêmio Osasco youth graduate, and made his senior debut for the club on 1 August 2012 by starting in a 2–3 home loss against
Palmeiras for the year's
Copa Paulista. On 31 January of the following year he moved abroad, signing a six-month loan deal with
F.C. Porto and being assigned to
the reserves in
Liga de Honra. Guilherme Lopes made his professional debut on 7 April 2013, coming on as a late
substitute for
Tozé in a 2–0 home win against
F.C. Arouca; it was his only appearance for the club before his loan expired. He subsequently served another temporary stint at
Audax Rio de Janeiro before being released. On 6 November 2015 Guilherme Lopes signed for
Independente de Limeira, after previously representing
Nova Iguaçu.{{cite web|url=https://globoesporte.globo.com/sp/campinas-e-regiao/noticia/2015/11/com-passagem-pelo-porto-meia-vai-atuar-pelo-independente-na-serie-a2.html|title=Com passagem pelo Porto, meia vai atuar pelo Independente na Série A2 ==References==