Independent North Palm Beach luxury real estate broker Liam Costner, 29, son of Kevin Costner and Bridget Rooney, turns 30 on November 15, 2026. Born November 15, 1996, he surfaces as a real-estate name, not a film credit. “Broker” is the shorthand. No Florida license number here makes broker, broker associate, or sales associate a verified class.
Famous sons are supposed to join the business or denounce it. He has done neither on the record. DNA reporting settled paternity. A 2005 marriage put oilman William “Bill” Koch in his mother’s house. Secondary sources place him in northern Palm Beach luxury property.
The 1996 DNA Verdict
Not the birth. The doubt.
Bridget Rooney, linked to the Rooney family and the Pittsburgh Steelers and described in People-sourced reporting as a niece of then-owner Dan Rooney, had a brief relationship with Kevin Costner. Liam was born November 15, 1996. Costner reportedly questioned paternity and sought a test. People and other mainstream accounts say Rooney insisted. DNA confirmed he was the biological father. No court order and no subpoena are in the sourced record. Reportedly requested. Not judicially compelled.
Reporting says Costner then set up a sizable trust fund and visited occasionally, not regularly. That cadence is the coverage’s, including a friend of Rooney’s cited in that reporting, not a complete private ledger. The fund’s size, rules, managers, and present value are unpublished. Provision is not presence.
Split what headlines fuse. Biological paternity: DNA reportedly confirmed Kevin Costner as the father. Family connection: Liam has six paternal half-siblings. Independent identity: the surname alone did not create a public acting career.
The Koch Enclave
In 2005 Bridget Rooney married William “Bill” Koch, a Koch-family businessman and oil executive. Liam was about nine. Secondary sources call Koch a billionaire, a label that stays reported rather than audited. Daughter Kaitlin Koch was born in 2006. Hollywood on one side, industrial money on the other. The file supports the marriage and a private profile. It does not support Koch blocking typecasting or steering Liam off acting.
Profile grid
| Profile Metric | Verified Detail |
| Full legal name | Liam Costner is the publicly reported name; a fuller legal name has not been independently verified in the supplied material. |
| Age in 2026 | 29 as of October 21, 2026; turns 30 on November 15, 2026. |
| Core specialty | Reported luxury residential real estate, with a focus on Northern Palm Beach County, Florida. |
| Paternity status | Kevin Costner’s biological son; DNA confirmation is reported in mainstream celebrity coverage. |
| Stepfather’s corporate identity | William “Bill” Koch, businessman and oil executive; billionaire status is reported by secondary sources. |
| Primary sibling count | Seven half-siblings: six through Kevin Costner and one through Bridget Rooney. Bill Koch’s children from other relationships should not automatically be included in this count. |
Who is Kevin Costner’s son Liam?
Liam Costner is the publicly reported son of Kevin Costner and Bridget Rooney, born November 15, 1996, and tied in secondary coverage to Florida real estate rather than acting.
Two sides of the sibling map
Through Kevin Costner: Annie, Lily, and Joe with Cindy Silva; Cayden, Hayes, and Grace with Christine Baumgartner.
| Half-sibling | Reported birth year |
| Annie Costner | 1984 |
| Lily Costner | 1986 |
| Joe Costner | 1988 |
| Cayden Costner | 2007 |
| Hayes Costner | 2009 |
| Grace Costner | 2010 |
Through Bridget Rooney, one maternal half-sibling:
| Half-sibling | Reported birth year |
| Kaitlin Koch | 2006 |
Six paternal half-siblings, one maternal. Koch’s children from other relationships may be step-siblings. They are not maternal half-siblings and stay out of the seven.
Closing the Coastal Deals
What does Liam Costner do for a living?
Liam Costner is publicly reported to work in real estate, with secondary sources associating him with luxury residential property in Northern Palm Beach County, Florida.
Secondary copy spells the shop “Frankel Bell,” “Frankel-Ball,” and “Frankel Ball.” One employer. The firm’s site says Frankel Ball Realty Group, LLC, also Frankel Ball Realty and Frankel-Ball Realty, at 3535 Military Trail #101, Jupiter, Florida 33458. Thomas Frankel and Brad Ball are the owners and brokers. The work is luxury waterfront and club property across the Palm Beaches.
The map named with him runs Palm Beach, Jupiter Island, Jupiter, and Palm Beach Gardens — northern-county docks and club streets. Context, not his deal sheet. No client, listing, price, or volume in this material is his.
A LinkedIn-derived profile lists Frankel-Ball Realty from January 2020, a producer role at NFP in November 2022, and Aspen Skiing Company in December 2022. Reported entries, not verified employment. Public agent pages reviewed for the firm show no Liam Costner bio. The link is an association, not a confirmed desk.
Is Liam Costner a real estate broker?
He is reported to work as a real estate agent. His specific Florida license class and broker designation have not been established by the supplied records.
Florida’s Department of Business and Professional Regulation licensee search is what would authorize “broker” or “broker associate.” Without a number, “chose real estate over Hollywood” is an editorial contrast, not a credential and not a rejected acting career.
| Evidence level | Editorial treatment |
| Reported professional identity | Liam is publicly associated with real estate rather than acting. |
| Reported market specialization | Secondary sources connect him with luxury residential property in Northern Palm Beach County. |
| Unverified performance measures | Individual transactions, annual sales volume, rankings, commission income, client roster, and licensing classification should not be asserted without supporting records. |
Is Liam Costner an actor like his father?
The available reporting identifies Liam with real estate rather than an acting career. There is insufficient evidence here to claim he pursued acting and deliberately rejected it.
Who is Liam Costner’s mother?
His mother is Bridget Rooney, who married businessman William “Bill” Koch in 2005.
How many siblings does Liam Costner have?
The supplied family account identifies seven half-siblings: six through Kevin Costner and one through Bridget Rooney.
The Architecture of Absolute Discretion
Kevin Costner’s career makes the surname legible. Liam is not established as a public-facing entertainment professional, so the crowd arrives for the father and finds the son’s trade only half visible.
He is described as private and largely out of the Hollywood spotlight. A limited public footprint does not prove he has no social accounts, refused press on principle, or designed a career to dodge fame.
Clients and closings would prove the trade. None are documented for him here. The reported occupation still names work that is not a credit list.
No rebellion is on the record, and the script does not require one. He is Kevin Costner and Bridget Rooney’s son, tied to a film family and to Bill Koch, the oil executive secondary sources call a billionaire, and associated with Florida luxury real estate at Frankel Ball Realty Group. Nothing established shows him chasing roles, declining Hollywood, taking a career order from his stepfather, or treating anonymity as a mission. The family draws the attention. The reported job keeps the story off a backlot.
