Hart Kail: Everything to Know About Michelle Williams’ Son

Hart Kail is the son of actress Michelle Williams and theatre director Thomas Kail. He was born in 2020 and is Michelle’s second child. Hart is also the younger half-brother of Matilda Ledger, Michelle’s daughter with the late actor Heath Ledger. His parents have kept most details about his childhood private.

Quick Facts About Hart Kail

How Old Is Hart Kail?

Hart Kail was born in 2020. Multiple secondary sources report that he was born in June 2020, but his exact date of birth has not been publicly confirmed.

Hart is 6 years old in 2026 based on the reported June 2020 birth month.

Hart Was Born During the COVID-19 Pandemic

Hart was born during the COVID-19 pandemic.

Michelle Williams later discussed what it was like to welcome a child during that unusual period. In a May 2022 interview with Variety, she explained that Hart’s arrival reminded her that life continued despite what was happening around the world.

She also said that her young son was experiencing the happiness of discovering the world without understanding the difficult circumstances surrounding his birth.

Hart Kail’s Birthplace

Hart’s exact birthplace has not been publicly confirmed.

Michelle and Thomas have shared very few details about his birth and early childhood.

Who Is Hart Kail’s Mother, Michelle Williams?

Hart’s mother is Michelle Ingrid Williams, an American actress born on September 9, 1980, in Kalispell, Montana.

Michelle began acting at a young age and became widely known through the television series Dawson’s Creek.

Her film and television work includes Brokeback Mountain, Blue Valentine, The Greatest Showman, Venom, The Fabelmans and Fosse/Verdon.

Michelle has received major recognition for her acting, including Golden Globe and Emmy awards. She has also received multiple Academy Award nominations.

Hart is Michelle’s second child and her first child with Thomas Kail.

Who Is Hart Kail’s Father, Thomas Kail?

Hart’s father, Thomas Kail, is an American theatre and television director.

He is best known for directing the Broadway musical Hamilton, created by Lin-Manuel Miranda.

Thomas has also worked on Fosse/Verdon, the television miniseries in which Michelle Williams played Broadway performer Gwen Verdon.

His theatre work has earned him major recognition, including a Tony Award.

How Did Michelle Williams and Thomas Kail Meet?

Michelle and Thomas met while working on Fosse/Verdon.

Michelle starred in the series, while Thomas worked as a director and executive producer.

Their relationship later became public. They reportedly became engaged in December 2019.

Around the same time, news emerged that Michelle was expecting a child.

Michelle Williams Was Pregnant With Hart in 2020

Michelle appeared with Thomas at the Screen Actors Guild Awards in January 2020 while pregnant with Hart.

She wore a black off-the-shoulder custom Louis Vuitton gown at the event.

Hart arrived later that year.

Michelle Williams and Thomas Kail’s Marriage

Michelle and Thomas reportedly married in March 2020.

Hart was born a few months after their marriage.

Before Thomas, Michelle was married to musician Phil Elverum. They married in 2018 and separated in early 2019.

Hart Is Michelle Williams’ Second Child

Hart is the second of Michelle Williams’ four children.

Michelle first became a mother in 2005 when she welcomed Matilda Rose Ledger with actor Heath Ledger.

Nearly 15 years later, she welcomed Hart with Thomas Kail.

Hart is also the eldest of Michelle and Thomas’ three children together.

Hart Kail’s Older Half-Sister Matilda Ledger

Hart’s older half-sister is Matilda Rose Ledger.

Matilda was born on October 28, 2005, in New York City. Her parents are Michelle Williams and the late Australian actor Heath Ledger.

Hart and Matilda share the same mother but have different fathers.

Michelle has worked to keep Matilda and her younger children away from unnecessary public attention.

Who Was Heath Ledger?

Heath Ledger was an Australian actor and the father of Hart’s older half-sister, Matilda.

He was known for films including 10 Things I Hate About You, Brokeback Mountain and The Dark Knight.

Michelle Williams and Ledger became a couple after meeting while working on Brokeback Mountain. They welcomed Matilda in 2005 and separated in 2007.

Ledger died in January 2008 from an accidental drug overdose.

Michelle and Ledger were never married.

Hart Kail’s Younger Sibling Born in 2022

Michelle and Thomas welcomed another child in 2022.

The baby was their second child together and Michelle’s third child overall.

Michelle was seen pregnant at the Cannes Film Festival in May 2022. Later that year, she and Thomas were seen in New York City with a newborn.

The couple has not publicly revealed the child’s name or gender.

Hart’s Youngest Sister Was Born in 2025

Michelle and Thomas expanded their family again in 2025.

Their youngest child is a girl who was born through gestational surrogacy.

Reports about the baby became public in April 2025. A source said she had arrived about six weeks earlier.

Michelle later confirmed during an August 2025 appearance on Jimmy Kimmel Live! that the child is a girl.

The girl’s name has not been publicly revealed.

Michelle Williams Thanked Her Surrogate

During her Jimmy Kimmel Live! appearance, Michelle explained that her youngest daughter had been born with the help of a surrogate named Christine.

Michelle publicly thanked Christine for helping bring her daughter into the world.

This makes Hart one of four children in Michelle Williams’ family.

Hart Kail’s Siblings

Hart has three siblings.

His older maternal half-sister, Matilda Rose Ledger, was born in 2005.

His younger sibling was born to Michelle and Thomas in 2022. The child’s name and gender have been kept private.

His youngest sister was born through surrogacy in early 2025. Her name is also private.

Matilda’s Relationship With Hart and Her Younger Siblings

Michelle has not shared many details about the relationships between her children.

However, reports indicate that Matilda is close to her younger siblings. A source told People in 2025 that she was doting on them.

Michelle also discussed their family Christmas plans during a November 2022 appearance on Live with Kelly and Ryan.

She said Matilda loved classic Christmas movies and was excited for her to share them with the younger children.

Hart Kail Loves Christmas and Reindeer

Michelle has revealed very few personal details about Hart.

One small detail came during her November 2022 appearance on Live with Kelly and Ryan.

Michelle said Hart loved Christmas songs and Santa’s reindeer. At the time, he was trying to learn the names of the reindeer.

She also said he was allowed three songs before bed and wanted all three to be Christmas songs.

Hart Kail’s Education

Hart’s school and other educational details have not been publicly disclosed.

His parents have kept this part of his childhood private.

Does Hart Kail Make Public Appearances?

Hart has largely been kept away from public events and media attention.

There are no major confirmed solo public appearances by Hart in the information available.

His parents regularly attend film, television, theatre, and award events, but this does not mean Hart attends those events with them.

Does Hart Kail Have Social Media?

Hart does not have any verified public social media accounts.

He is still a young child, and his parents have generally protected his privacy.

Does Hart Kail Have a Career?

Hart does not have a public career or profession.

There is no reliable information showing that he has worked as an actor, model, performer, or in another part of the entertainment industry.

Hart Kail’s Net Worth

Hart Kail does not have a confirmed personal net worth.

His parents are successful in the entertainment industry, but their money should not be treated as Hart’s personal wealth.

Hart Kail’s Life Today

Hart continues to grow up mostly outside the public spotlight.

His parents have not publicly shared details about his school or everyday routine.

As of 2026, Hart is the eldest of Michelle Williams and Thomas Kail’s three children together and the younger half-brother of Matilda Ledger.

Facts About Hart Kail

• Hart Kail was born in 2020.
• His birth month is reported as June.
• His exact birthday has not been publicly confirmed.
• He is 6 years old in 2026 based on the reported birth month.
• He was born during the COVID-19 pandemic.
• His mother is actress Michelle Williams.
• His father is theatre director Thomas Kail.
• His parents met while working on Fosse/Verdon.
• Michelle and Thomas reportedly married in March 2020.
• Hart is Michelle Williams’ second child.
• He is Michelle and Thomas’ first child together.
• His older half-sister is Matilda Rose Ledger.
• Matilda’s father was actor Heath Ledger.
• Hart has two younger siblings.
• One younger sibling was born in 2022.
• His youngest sister was born through surrogacy in 2025.
• Michelle said Hart loved Christmas songs and Santa’s reindeer as a young child.
• His school has not been publicly identified.
• He has no verified public social media accounts.
• He has no publicly established career.
• His personal net worth is not known.

Read More: Matilda Ledger: Where Is Heath Ledger’s Only Daughter Now?