A "nosy parker", sometimes spelled 'nosey parker', is a person of an overly inquisitive or prying nature.

The phrase 'nosy parker' dates from the end of the 19th century. The popular Victorian novelist Mary Elizabeth Braddon edited the Belgravia Magazine at that time and 'nosey parker' appeared there in the May 1890 edition, which seems to be the first example of the phrase's use in print:

You're a asking' too many questions for me, there's too much of Mr. Nosey Parker about you, an' I'd 'ave you to know as I'm a laidee.