The Patron Saint of Cross-Dressers

The body of Santa Marina, Santa Maria Formosa, Venice
Encased in a small casket in the church of Santa Maria Formosa is an embalmed figure (with the skull still visible) surrounded by flowers. 

This is Santa Marina, an eighth century 'monk' from Lebanon. In 1230 her relics were 'translated' (some would say stolen) from Constantinople and moved to Venice, where a church was dedicated to her. 

The church was destroyed in the early 19th century and her body was moved to Santa Maria Formosa, where it remains to this day. 
Shrine to Santa Marina, Campo Santa Marina, Venice
A shrine in Campo Santa Marina marks the spot where the church once stood. 

Santa Marina's life story is more colourful than that of many saints. It seems that she spent the whole of her adult life in a monastery pretending to be a monk. It was only when she died, and her body was being prepared for burial, that her secret was revealed! 

Santa Marina doesn't seem to be the patron saint of anybody or anything, but I think she could be a good candidate as the patron saint for cross-dressers.