John Grayken

John Patrick Grayken (born June 1956) is an American-born Irish billionaire financier, the founder and chairman of the private equity firm Lone Star Funds.

Forbes magazine ranked Grayken 424th in the list of World's Billionaires and listed his wealth as totaling $6.9 billion for 2024.

Early life John Patrick Grayken was born in June 1956, and was brought up in Cohasset, Massachusetts, a suburb of Boston. He received a BA degree in economics from the University of Pennsylvania, and an MBA from the Harvard Business School in 1982.

Grayken served as the managing general partner of the Brazos Fund, a vulture fund founded by Bass in 1995. The fund aimed to buy mortgage-related assets from the banking industry, including from the Resolution Trust Corporation.

Grayken founded Lone Star, the successor to the Brazos Fund, in 1995.

In 1999, Grayken became an Irish citizen, "for tax purposes", renouncing his American citizenship.

Philanthropy In March 2017, Eilene and John Grayken gave a $25 million gift to the Boston Medical Center (BMC) to create the BMC Grayken Center for Addiction Medicine. The gift is the largest donation in BMC's history.

In April 2017, John P. Grayken gave a leadership gift to the Wharton School of the University of Pennsylvania to fund the Grayken Program in International Real Estate at the Wharton School.

In February 2019, Grayken and his wife made a $10 million gift to create the Grayken Center for Treatment at South Shore Health, a non-profit, charitable health system in southeastern Massachusetts offering outpatient treatment for substance use disorders. The Center also serves pregnant and postpartum women facing behavioral health disorders.

Grayken and his wife made a 2022 donation of £50 million to the Great Ormond Street Hospital, earmarking the funds for researching treatment of childhood illnesses.

Personal life Grayken divorced his first wife soon after he became a "tax refugee"; they reunited within a month of the final divorce decree, but divorced again six months later. Grayken later married actress Eilene Davidson in London, a British theatre producer and former actress. They have four children.

As of 2015, they owned Pyrford Court, Surrey, which features prominently in the 1976 movie, The Omen. Pyrford Court is a Grade II listed 15-bedroom house, built in 1910 for Rupert Guinness, 2nd Earl of Iveagh.