Negative Keywords are terms added to an Apple Ads search results campaign or ad group that stop the ad from showing for matching searches, cutting wasted spend and campaign overlap.
Negative keywords work in reverse: instead of telling Apple Ads where to show an ad, they tell it where not to. They can be added at the campaign or ad group level and apply only to search results ads, the one Apple Ads placement that uses keywords. Like bidded keywords they carry a match type, and the two behave very differently. An exact-match negative, the default, blocks only that exact term, not its close variants or reordered versions. A broad-match negative blocks any search that contains all of its words, in any order, which Apple suggests when an ad should never appear for a word or phrase.
Their main job is traffic control. Apple's campaign-structure guidance adds every brand, category and competitor keyword to the discovery campaign as an exact-match negative, so broad match and Search Match hunt for new queries instead of bidding against your own exact campaigns. Negatives also retire terms that draw taps but not installs, and screen out searches with the wrong intent; Apple's own example is a women's fitness app excluding "men's fitness". In our experience, a regular pass through the Search Terms report for mismatches is one of the cheapest ways to lower cost per install.
Example
A budgeting app's discovery campaign keeps matching "free budget template" and "budget template printable", searches from people who want a spreadsheet rather than an app. The team adds "budget template" as a broad-match negative to block both, then adds its brand keywords to the discovery campaign as exact-match negatives.