The next Foundations of Computational Mathematics conference will take place in Barcelona, between July 10th - 19th, 2017. The conference will follow a format tried and tested to a great effect in former FoCM conferences: plenary invited lectures in the mornings, theme-centred parallel workshops in the afternoons. Each workshop extends over three days and the conference will consist of three periods, comprising of different themes. Although some participants choose to attend just one or two periods, on past experience the greatest benefit follows from attending the conference for its full ten days: the entire idea of FoCM is that we strive to break out of narrow boundaries of our specific research areas and open our minds to the broad range of exciting developments in computational mathematics. Each workshop will include a daily "semi-plenary" lecture, of interest to a more general audience, as well as (typically shorter) talks aimed at more technical audience. The choice of the speakers of a workshop is the responsibility of workshop organisers, and most of these workshop talks will be by invitation. We have every intention to build upon previous FoCM conferences and to make FoCM 2017 into a unique meeting point of workers in computational mathematics and of theoreticians in mathematics and in computer science. While presenting plenary talks by foremost world authorities and maintaining the highest technical level in the workshops, the emphasis will be on multidisciplinary interaction across subjects and disciplines, in an informal and friendly atmosphere. We hope that it will be an opportunity to meet colleagues from different subject-areas and identify the wide-ranging (and often surprising) common denominator of our research.