Selecting supplemental content for inclusion in a search results page

Disclosed are various embodiments that involve selecting supplemental content to be included in a search results page. A search query is received. A set of search results is generated by executing a search based at least in part on the search query. A subset of supplemental content providers is selected based at least in part on respective relevancies of the supplemental content providers to the search query. A search results page is generated. The search results page is configured to present supplemental content from the subset of supplemental content providers in association with the set of search results.