In 1970, K. R. Perry, Doug Perry, and Macon Brock started K&K Toys in Norfolk, Virginia. This mall concept grew to over 130 stores on the East Coast.

Brock and the co-founders of Dollar Tree got the idea for the company from another retailer known as Everything's A Dollar, which went bankrupt in the 1990s.

In 1991, the corporation made a decision to focus exclusively on the expansion of dollar stores after selling K&K stores to KB Toys, owned by Melville Corporation.

In 1993, the name Only $1.00 was changed to Dollar Tree Stores to address what could be a multi-price-point strategy in the future, and part equity interest was sold to SKM partners, a private equity firm.

On March 6, 1995, Dollar Tree, Inc. went public on the NASDAQ exchange at $15 a share, with a market cap then calculated at $225 million.

In 1996, Dollar Tree acquired Dollar Bill$, Inc., a Chicago-based chain of 136 stores.

In 1997, the company opened its first distribution center and its new store support center, both located in Chesapeake, Virginia.

In 1998, Dollar Tree acquired 98-Cent Clearance Centers in California.

In 1999, Dollar Tree acquired Only $One stores based in New York state.

That same year, the company opened its second distribution center in Olive Branch, Mississippi.

In 2000, Dollar Tree acquired Dollar Express, a Philadelphia-based company, and also built a new distribution center in Stockton, California.

In 2003, Dollar Tree acquired Salt Lake City, Utah-based Greenbacks, Inc., and opened a new distribution center in Marietta, Oklahoma.

In 2004, Dollar Tree opened its first store in North Dakota which marked its operation of stores in all 48 contiguous states. The company also opened new distribution centers in Joliet, Illinois, and Ridgefield, Washington.

In 2007, Dollar Tree expanded its Briar Creek Distribution Center, crossed the $4 billion sales threshold, and had a market capitalization of $3.29 billion.

In 2008, Dollar Tree earned a place in the Fortune 500.

In 2009, Dollar Tree redesigned its website with a new e-commerce platform.

By the close of 2009, the company opened a store in Washington, D.C.

In 2010, the corporation opened its 4,000th chain store and acquired 86 Canadian Dollar Giant stores which are based in Vancouver, British Columbia. The stores are operated in British Columbia, Alberta, Saskatchewan, and Ontario. These are the first retail locations outside of the United States operated by Dollar Tree.

In 2011, Dollar Tree achieved total sales of $6.63 billion, opened 278 new stores, and completed a 400,000 square-foot expansion of its distribution center in Savannah, Georgia.

In 2012, Dollar Tree opened another 345 new stores and exceeded $7 billion in sales, with an end-of-the-year market cap at $9.13 billion.

On July 28, 2014, Dollar Tree announced that it was offering $9.2 billion for the purchase of competitor chain store Family Dollar.

On August 18, 2014, Dollar General lodged a competing bid of $9.7 billion for Family Dollar.

The bid was rejected on August 20, 2014, by the Family Dollar board, which said it would proceed with the deal with Dollar Tree.

In January 2015, Dollar Tree announced plans to divest 300 stores in order to appease US regulators scrutinizing its proposed takeover of Family Dollar stores.

In June 2015, the firm agreed to sell 330 stores to private equity company Sycamore Partners as part of the approval process for its $8.5 billion takeovers of Family Dollar.

The company was ranked 134 on the 2018 Fortune 500 list of the United States corporations by revenue.

In March 2019, as part of its reposition plan, Dollar Tree announced that it will close up to 390 Family Dollar stores along with renovating 1,000 other locations.

On March 3, 2021, it was announced that Dollar Tree had quietly introduced a combination Family Dollar/Dollar Tree store concept with the first one opening in late 2019. Dollar Tree has opened and operated nearly 50 locations by the end of 2020, primarily in small towns with populations of just a few thousand people.

On September 28, 2021, CEO Michael Wytinski, citing increased shipping and labor costs squeezing profit margins, announced that some prices will be rising above $1, possibly to as much as $1.50.

In 1986, Doug Perry, Macon Brock, and Ray Compton started another chain store called Only $1.00 with five stores, one in Georgia, one in Tennessee, and three in Virginia. The expansion of dollar stores was continued alongside K&K Toys stores, mostly in enclosed malls.

In 1953, K. R. Perry opened a Ben Franklin variety store in Norfolk, Virginia, which later became known as K&K 5&10.