Scheduled for launch in 2020, the Euclid mission will survey the entire extragalactic sky in the optical and near infrared (NIR) with a central goal of constraining cosmology through observations of large-scale structure. This workshop is dedicated to the preparation for the construction and cosmological analysis of the Euclid galaxy cluster catalog. The Euclid survey will produce a catalog estimated to contain of order 100,000 clusters extending out to redshifts well beyond unity. The meeting aims to bring together experts working on cluster detection and cosmological analysis to discuss methodology, compare codes and to reflect on the context of cluster cosmology in the Euclid era. This will be a small, dedicated workshop of 40-50 participants with ample time for informal discussion in addition to presentations.