Meet Julia Margaret Flesher Koch (born April 12, 1962) is an American socialite, billionaire, philanthropist, and one of the richest women in the world. She inheriting a 42% stake in Koch Industries from her late husband David Koch.

David Koch was a former executive and co-owner of Koch Industries, the second-largest closely held company in the US. David Koch died in August 2019 at age 79, controlled a fortune estimated at $53.5 billion. Forbes, however, estimates her wealth to be significantly less, at $44.9 billion, which would make her the third-richest woman in the world after Francoise Bettencourt Meyers and Alice Walton. She was ranked at #18 in the Forbes Billionaires 2020 list.

An Iowa native who graduated from the University of Central Arkansas, she moved to New York in the 1980s and worked as an assistant to designer Adolfo and used to help style and dress former first lady Nancy Reagan. In 1991, friends set up Julia and David on a blind date, which did not go well. They ran into each other again six months later and dated for five years before marrying in 1996.

She is beloved amongst New York society for her style and generosity in the US state. She has been known to give large amounts of money to arts organisations.

Koch serves as the president of the David F. Koch Foundation, which has donated nearly $200 million to various philanthropic causes such as medical research and the arts.

During her husband's lifetime, they made donations to institutions such as the Lincoln Center, the Metropolitan Museum of Art, and the Smithsonian Museum of Natural History.

With her husband, she has donated $10 million to Mount Sinai Medical Center and $10 million to Stanford's Children's Hospital to study food allergies.

Koch and its Stand Together community the Family Independence Initiative have raised more than $19 million through the #GiveTogetherNow initiative to provide direct cash assistance to families impacted by COVID-19.

Koch also left behind at least $143 million worth of real estate in New York City, the Hamptons, Aspen, and Florida, but the fate of those properties after his death is unknown.

The discrepancy could be explained by different estimates of how much Koch left to his wife versus his three children, as well as fluctuations of the valuation of Koch Industries.

These are just some of the sources of Julia's wealth, thanks to Koch Industries:

• Revenue for Flint Hills Resources and its chemicals business, as well as Koch Pipelines and Koch Fertilizer, is calculated to be $39 billion by comparing their reported production capacities with select industry peers.

• Based on information from credit reports and people familiar, paper and pulp producer Georgia-Pacific had $21 billion of revenue, and polymer and fiber producer Invista had revenue of $4 billion. Electronic components manufacturer Molex had revenue of $5.5 billion.

• Infor Global Solutions, an enterprise software company, had revenue of $3.1 billion and is 45% owned by Koch.

• Of the remaining group revenue of $33.9 billion, 90%, is attributed to Koch's commodity trading business. The remaining $3.6 billion is attributed to Koch's other businesses and is included at a price-to-sales multiple of one. Valuation details for the units analyzed individually can be found in the asset notes for each.

• Also, $30.4 billion in short-term assets is held at the Koch Industries parent, based on Moody's reports stating that the company has a zero net debt position.

• Koch's cash investments were included at $2 billion in 2015, based on a March 2016 Bloomberg report, and applied to a generalized asset allocation since then.