The 2021 edition of the CHATS on Applied Superconductivity Workshop was organized jointly by the ITER International Organization and CEA Cadarache. Owing to the pandemic conditions, it was held virtually on 20-24 September 2021.

The CHATS-AS 2021 workshop counted up to 70 participants from nearly 20 different institutions, and 34 oral presentations and discussions. The virtual format did not affect the customary informal atmosphere, and the discussion in the five tracks (Mechanical Modeling, Quench, Multi-scale, Electromagnetics and Tools) was lively and fruitful. The format, with sessions of limited duration distributed through the five days, was particularly well adapted to the virtual workshop, allowing for a balanced worldwide participation.