Quick Facts
| Full Name | Liam (Timothy) Costner |
| Born | 1996 (sources vary between mid-October and mid-November 1996) |
| Birthplace | United States |
| Father | Kevin Costner (actor, director) |
| Mother | Bridget Rooney |
| Stepfather | Bill Koch (businessman) |
| Half-siblings | Annie, Lily, Joe (from Kevin’s first marriage); Cayden, Hayes, Grace (from Kevin’s second marriage) |
| Profession | Real estate agent |
| Public profile | Very low — avoids media and social platforms |
Who Is Liam Costner?
Liam Costner is best known as the son that Hollywood actor Kevin Costner did not raise in the public eye. Unlike his six half-siblings, who occasionally appear alongside their father at premieres or family events, Liam has spent his adult life almost entirely out of the spotlight, working as a real estate agent rather than pursuing acting, producing, or any entertainment-industry career.
His story is unusual for a “celebrity kid” profile: it isn’t built on red carpets or Instagram posts, but on a short relationship between two well-known American families — the Costners and the Rooneys — and a paternity dispute that made headlines in the mid-1990s.
Family Background: Kevin Costner and Bridget Rooney
Kevin Costner married Cindy Silva in 1978, and the couple had three children before divorcing in 1994. Shortly after that divorce, Costner had a brief relationship with Bridget Rooney, who would later marry billionaire businessman Bill Koch; Costner and Rooney had a son together, born in 1996. That son is Liam.
Bridget Rooney comes from one of America’s best-known sports families — she is connected to the family that has long owned the Pittsburgh Steelers NFL franchise. After her relationship with Costner ended, she married Bill Koch, giving Liam a stepfather from one of America’s wealthiest industrial families.
Kevin Costner went on to marry Christine Baumgartner in 2004, and the couple had three more children before divorcing in 2024 — meaning Liam is the only Costner child born between the two marriages, and the only one from the Rooney side of the family.
The Paternity Story
One detail that repeatedly surfaces in coverage of Liam Costner is that his father did not immediately acknowledge him. Multiple outlets, including reporting traced back to a 2002 People magazine story, describe Bridget Rooney requesting a paternity test to formally establish Kevin Costner as Liam’s father. Once confirmed, a private financial and custody arrangement reportedly followed, though neither party has spoken about it publicly in detail.
This episode is the most-documented part of Liam’s early life — far more than his adulthood, which both he and his parents have kept almost entirely private.
Career: Real Estate, Not Hollywood
Rather than following his father into acting, Liam Costner has built a career in real estate. Several biography sites and entertainment outlets identify him as an agent connected to a Florida-based realty group, working the Palm Beach County market. He has kept this career largely out of public promotion — there’s no evidence he has used the Costner name for marketing purposes, and he does not maintain an active public-facing social media presence to promote listings or a personal brand.
This is consistent with the broader pattern in his life: where several of his half-siblings have pursued careers touching entertainment (directing, acting) or have appeared publicly with their father, Liam has stayed in a conventional, non-celebrity profession.
Net Worth: Why the Numbers You’ll See Online Don’t Agree
This is worth being direct about. If you search for “Liam Costner net worth,” you will find wildly different figures — some articles claim around $800 million (based on assumptions about his stepfather Bill Koch’s fortune), others cite figures as low as $2–40 million, and some conflate Liam with an unrelated actor of the same name. None of these figures are backed by public financial disclosures, court records, or statements from Liam himself.
What can be said reliably:
- His stepfather, Bill Koch, is a billionaire industrialist, which has fueled speculation about Liam’s eventual inheritance.
- His biological father, Kevin Costner, has an estimated net worth in the hundreds of millions from his acting and business career.
- Liam’s own earned income comes primarily from real estate, a career that does not typically generate eight- or nine-figure wealth on its own.
Any specific net worth figure attached to Liam Costner personally should be treated as speculation rather than fact until he or a verified source confirms it.
Personal Life
Liam Costner has consistently avoided media interviews and keeps his relationships, home life, and day-to-day activities out of public view. He is not known to maintain an active, verified public Instagram or X account, which is part of why so much online content about him relies on recycled, unverified claims rather than direct quotes or statements.
Explore More: Jen Psaki Net Worth 2026: Inside the Former White House Press Secretary’s Earnings
FAQ
Is Liam Costner an actor like his father?
No. Public records and biography sources consistently describe his profession as real estate, not acting or filmmaking.
Who are Liam Costner’s parents?
His father is actor Kevin Costner; his mother is Bridget Rooney, who later married businessman Bill Koch.
Did Kevin Costner initially deny being Liam’s father?
Reporting traced to a 2002 People magazine story indicates Bridget Rooney sought a paternity test to confirm Costner as Liam’s father, suggesting there was initial uncertainty or reluctance before confirmation.
How many siblings does Liam Costner have?
Six half-siblings: Annie, Lily, and Joe from Kevin Costner’s first marriage, and Cayden, Hayes, and Grace from his second marriage.
What is Liam Costner’s real net worth?
It isn’t publicly verified. Widely circulated figures online (ranging from a few million to hundreds of millions) are unsourced estimates, not confirmed financial data.
Accuracy Note
The core facts in this article — Kevin Costner’s marriages, his relationship with Bridget Rooney, and Liam’s 1996 birth — are drawn from Kevin Costner’s Wikipedia biography, which is sourced to contemporaneous reporting. Details about Liam’s career and the paternity dispute are corroborated across several independent biography sites, though his exact birth date (reported as either October 15 or November 15, 1996) and his net worth remain inconsistently reported and should be presented to readers as such — not as confirmed fact.
I’m Muhammad Ubaid, founder of YBR Magazine. I research and write detailed guides on America’s National Parks — covering entry fees, permits, best times to visit, and planning tips — using official NPS sources and up-to-date information.
