Stenostiridae, or the fairy flycatchers, are a family of small passerine birds proposed as a result of recent discoveries in molecular systematics. They are also referred to as stenostirid warblers.
This new clade is named after the fairy flycatcher, a distinct species placed formerly in the Old World flycatchers. This is united with the "sylvioid flycatchers": the genus Elminia (formerly placed in the Monarchinae) and the closely allied former Old World flycatcher genus Culicicapa, as well as one species formerly believed to be an aberrant fantail.
The Stenostiridae as a whole are related to penduline tits, titmice and chickadees. All these appear to be closer to the Sylvioidea than to other Passerida, but this is not robustly supported by the available data and they might constitute a distinct, more basal superfamily.