I don't have any fleece sweaters but have a fleece jersey and light-weight fleece outerwear.

I wash them in cold water with regular detergent.
You should turn them inside out and if they are "delicate" wash them in a mesh garment bag.


I dry in the dryer with the temperature set to low heat or delicate. If you're not sure about drying lay it on a towel on a flat surface to dry.