Drummond grew up on the grounds of a country club in Bartlesville, Oklahoma, and graduated from Bartlesville High School in 1987. She left Oklahoma to attend college at the University of Southern California in Los Angeles, where she majored in journalism and then gerontology. Drummond planned to attend law school in Chicago and live in a big city, but her plans changed when she met and married her husband, Ladd Drummond, a fourth-generation member of a prominent Osage County cattle ranching family, whom she now calls "the Marlboro Man" in her blog. She moved to his ranch north of Pawhuska, and they had four children.

She began blogging in May 2006, writing about topics such as ranch life and homeschooling. About a year later she posted her first recipe and a tutorial on "How to Cook a Steak" accompanied by 20 photos explaining the cooking process in what she calls "ridiculous detail". Her stories about her husband, family, and country living, and her step-by-step cooking instructions and elaborate food photography, proved highly popular with readers. Confessions of a Pioneer Woman won honors at the Weblog Awards (also known as the Bloggies) in 2007, 2008, and 2009, and in 2009 it took the top prize as Weblog of the Year.

As of September 2009, Drummond's blog reportedly received 13 million page views per month. An article in the Toronto Globe and Mail described it as "[s]lickly photographed with legions of fans . . . arguably the mother of all farm girl blogs." The blog has been referenced in the Los Angeles Times, The New York Times, and BusinessWeek.

Drummond's first cookbook, The Pioneer Woman Cooks, was published in October 2009 after reaching the top spot on Amazon.com's preorder list for hardcover books. A New York Times reviewer described Drummond as "funny, enthusiastic and self-deprecating", and commented: "Vegetarians and gourmands won’t find much to cook here, but as a portrait of a real American family kitchen, it works."

The Pioneer Woman wrote a series on her blog titled From Black Heels to Tractor Wheels chronicling her would-be move from L.A. to Chicago when she met a cowboy and changed her plans. The series will be published as a book Valentine's Day 2011 and the movie rights have been sold to Columbia Pictures. Reese Witherspoon is rumored to be playing Ree.