Dear Colleagues, This is the first announcement for a "Workshop in Category Theory and Algebraic Topology," which will take place at the UCL in Louvain-la-Neuve, Belgium, from Thursday 10 to Saturday 12 September 2015. The following invited speakers have accepted to give a talk at the workshop: Joachim Kock (Universitat Autònoma de Barcelona) Steve Lack (Macquarie University) Tom Leinster (University of Edinburgh) Sandra Mantovani (Università degli Studi di Milano) Ieke Moerdijk (Radboud Universiteit Nijmegen) Fernando Muro (Universidad de Sevilla) Emily Riehl (Harvard University) Tim Van der Linden (Université catholique de Louvain) (see the webpage of the conference at the address http://sites.uclouvain.be/ctat2015/ for more information). Some practical information concerning registration will be sent in a second announcement at the beginning of 2015. We look forward to seeing you in Louvain-la-Neuve! Best wishes, Kathryn Hess, Marino Gran, Jérôme Scherer and Enrico Vitale [For admin and other information see: http://www.mta.ca/~cat-dist/ ]