The Climate Forecast System (CFS) is a coupled global climate model used for operational intraseasonal-to-interannual (ISI) prediction at the National Centers for Environmental Prediction (NCEP). NCEP developed CFSv2 over the course of several years and implemented it into operations in March 2011. External community research supported by the Climate Program Office (CPO) enhanced core internal development and evaluation. To bring the broader climate research and applications community together with NCEP scientists to evaluate the utility of CFSv2 for climate modeling research and as a climate forecast tool, the NCEP Climate Prediction Center (CPC), NOAA Climate Test Bed (CTB), Center for Ocean-Land-Atmosphere Studies (COLA), and NOAA CPO organized a CFSv2 Evaluation Workshop in 2012. This topical collection on Climate Forecast System Version 2 (CFSv2) includes a selection of peer-reviewed papers consisting of material presented at the workshop.