Resumo: We are pleased to announce the First Geant4 Tutorial Workshop in São Paulo (Geant4SP) that will take place in the Instituto de Física da Universidade de São Paulo from February 4 to February 8, 2019. The workshop is organized by the Centro de Ciências Naturais e Humanidades of the Universidade Federal do ABC, the Instituto de Física da Universidade de São Paulo (IFUSP) and the Instituto de Pesquisas Energéticas e Nucleares (IPEN). The workshop is mainly aimed to graduate students in the fields of Nuclear and Particle Physics and any field that deals with radiation and particle detection, as Medical Physics or material studies. Geant4 is a toolkit for simulating the passage of particles and radiation through matter written in C++ which runs on Linux, Mac OS and different types of UNIX flavours. Hence it is highly recommended that the participants have at least a basic level of understanding of C++ and UNIX like operational systems. The program will consist of invited plenary talks in the form of lectures and hands on activities, giving to the workshop the dynamics of a Tutorial. Participants are invited to bring their own laptop, allowing them to finish the Workshop with a working version of the code. The topics covered by the tutorial are: