A gadfly is a person who upsets the status quo by posing upsetting or novel questions, not just being an irritant. The term has been used to describe many politicians and social commentators.

In modern and local politics, gadfly is a term used to describe someone who persistently challenges people in positions of power, the status quo or a popular position.   For example, Morris Kline wrote "There is a function for the gadfly who poses questions that many specialists would like to overlook.  Polemics are healthy" Oxford University professor Bent Flyvbjerg has talked about "gadfly social science," emphasizing a key role for social science in identifying and challenging the abuse of power, whoever the perpetrator and whoever the victim.

The word may be uttered in a pejorative sense, while at the same time is accepted as a description of honourable work or civic duty.

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