The Denny Triangle is a neighborhood in Seattle, Washington, United States, that stretches north of the central business district to the grounds of Seattle Center. Its generally flat terrain was originally a steep hill, taken down as part of a mammoth construction project in the first decades of the 20th century known as the Denny Regrade, which is another name for the neighborhood on the regraded area. The name Denny Triangle, referring to the northeastern portion of this regrading project, is a term that has gained currency as this neighborhood has seen increasing development in the first decades of the 21st Century.
As with most Seattle neighborhoods, the Denny Triangle has no formal borders. The Seattle City Clerk's Neighborhood Map Atlas (which is published by the city but does not have official status as defining neighborhoods) defines the Denny Regrade as bounded on the north by Denny Way, on the southwest by Third Avenue, on the southeast by Olive Way, with a small eastern border on Interstate 5. A 2009 map from northwestplaces.com treats the term "Denny Regrade" as synonymous with Belltown and shows both names as referring to a triangle bounded on the north by Denny Way, on the southwest by Western Avenue (two blocks inland of the Central Waterfront), and on the southeast by Stewart Street; the southern tip of this triangle falls in the northern part of Pike Place Market. A map on downtownseattle.com agrees on the northern boundary at Denny Way, but splits this area into "Belltown" and the Denny Triangle and gives both a less regular shape. They divide Belltown to the southwest from the Denny Triangle to the northeast, with the border running mainly along Fifth Avenue but including a small number of properties along Denny Way west of Fifth Avenue as being in the Denny Triangle. They mark the southwest border of Belltown as a block closer to the water (Elliott Avenue) and draw a more ragged southeast border: west of Fifth Avenue, Belltown extends south only to Lenora Street, while east of Fifth Avenue the Denny Triangle is bounded in its westernmost block by Virginia Street and (once it crosses Westlake Avenue) by Olive Way, and with an eastern border on the same small piece of Interstate 5 as the City Clerk's map.