Since the beginning of the economic crisis in Spain young people have migrated abroad looking for job opportunities. In the meantime, after the 15-M movement in 2011, Spanish society created various social movements hoping to make change happen, as well as the pro-independence movement in Catalonia that gathered strength as a response to the Spanish economic and political crisis. This paper analyses how Spanish young people in London, as transmigrants rooted in two different countries, engage with the politics of their home country through two transnational social movements in London: ANC England and the Maroon Wave London. The article describes both local movements (comparing their goals, structure and activities), showing the reasons that young Spanish migrants get involved and their experiences within them. It also rethinks the nature and modalities of young diasporic identities and political engagement in the global age through the experiences of the young people interviewed.