The Marie Curie Alum­ni Asso­ci­a­tion (MCAA) is an inter­na­tion­al non-prof­it orga­ni­za­tion com­posed of an active, glob­al com­mu­ni­ty of sci­en­tif­ic researchers. The MCAA was estab­lished and is sup­port­ed by the Euro­pean Com­mis­sion, but entire­ly run by vol­un­teer mem­bers and with a bot­tom-up approach at its core. All MCAA mem­bers ben­e­fit or have ben­e­fit­ted from Marie Skłodows­ka-Curie Actions, which is the Euro­pean Union’s ref­er­ence pro­gram for doc­tor­al edu­ca­tion and post­doc­tor­al train­ing. MCAA mem­bers there­fore share a strong back­ground in research, but their career paths are diverse and touch all eco­nom­ic sec­tors. The vibrant MCAA com­mu­ni­ty brings togeth­er all career stages from all sci­en­tif­ic dis­ci­plines, encour­ag­ing net­work­ing and coop­er­a­tion, mak­ing the MCAA a forum of debate between researchers and with soci­ety. The MCAA is a major plat­form for researchers to con­tribute to shap­ing sci­ence pol­i­cy in Europe, pro­vid­ing career devel­op­ment oppor­tu­ni­ties, and sup­port­ing the wider research com­mu­ni­ty on top­ics affect­ing research and researchers’ lives. The MCAA also has 33 chap­ters locat­ed around the world as a way of facil­i­tat­ing com­mu­ni­ca­tion with its mem­bers and engag­ing them in the devel­op­ment of the MCAA.