Hart Kail is the son of American actress Michelle Williams and theater director Thomas Kail. He was born in 2020 during the COVID-19 pandemic and is Michelle’s second child and her first with Thomas.
Hart has an older half-sister, Matilda Ledger, and two younger siblings. His parents keep him mostly away from public attention, so only a few details about his childhood have been shared.
Hart Kail’s Quick Facts
| Detail | Information |
|---|---|
| Full name | Hart Kail |
| Birth year | 2020 |
| Reported birth month | June |
| Age | 6 years old as of October 2026 |
| Nationality | American |
| Mother | Michelle Williams |
| Father | Thomas Kail |
| Older half-sister | Matilda Rose Ledger |
| Younger siblings | Two |
| Known for | Being Michelle Williams and Thomas Kail’s son |
| Social media | No known public account |
| Net worth | No personal net worth is reliably known |
How Old Is Hart Kail?
Hart Kail was born in 2020.
Several reports give his birth month as June 2020, although his exact date of birth has not been publicly confirmed.
Based on the reported June 2020 birth month, Hart is 6 years old as of October 2026.
His exact birthplace has also not been publicly confirmed.
Hart Was Born During the COVID-19 Pandemic
Hart arrived during the COVID-19 pandemic.
Michelle later spoke about what it was like to welcome a child during such an uncertain time. She said the world they brought their baby into was different from what they had expected.
Hart, however, was too young to understand what was happening around the world. Michelle described him as experiencing the simple joy of discovering new things while growing up in a loving home.
She discussed the experience in a May 2022 interview with Variety.
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.
She became widely known through Dawson’s Creek and later built a film career.
Some of her best-known projects include:
- Brokeback Mountain
- Blue Valentine
- The Greatest Showman
- Venom
- The Fabelmans
- Fosse/Verdon
Michelle has received major awards and nominations for her acting.
She played Gwen Verdon in Fosse/Verdon, the project that also brought her together professionally with Hart’s father.
Who Is Hart Kail’s Father, Thomas Kail?
Hart’s father is Thomas Kail, an American theater and television director.
He is especially known for directing the Broadway musical Hamilton, created by Lin-Manuel Miranda.
Thomas also directed and executive-produced Fosse/Verdon.
His work on that television series introduced him to Michelle Williams, who starred in the lead role.
How Did Hart’s Parents Meet?
Michelle Williams and Thomas Kail met while working on Fosse/Verdon.
The series premiered in 2019, and reports say Michelle and Thomas had first met while making the project in 2018.
Their relationship later became public.
By December 2019, reports said they were engaged and expecting their first child together.
Michelle Williams and Thomas Kail Married in 2020
Michelle and Thomas married in 2020.
Reports place their wedding in March 2020.
A few months later, they welcomed Hart.
Hart is the first child Michelle and Thomas have together, although Michelle was already the mother of Matilda Ledger.
Michelle Was Pregnant With Hart at the 2020 SAG Awards
Michelle’s pregnancy became public in December 2019.
On January 19, 2020, Michelle and Thomas attended the 26th Annual Screen Actors Guild Awards at the Shrine Auditorium in Los Angeles.
Michelle attended the ceremony while pregnant with Hart.
She won the SAG Award for her performance in Fosse/Verdon that night.
Hart’s Name Was Kept Private
Michelle and Thomas did not immediately share many details about their son after his birth.
Even Hart’s name remained private for some time.
Reports later identified him publicly as Hart Kail.
His parents have continued to keep most details about his childhood away from the media.
What Has Michelle Williams Said About Hart?
Michelle does not often discuss Hart publicly.
One of her most detailed comments came during her 2022 Variety interview.
She spoke about raising a baby during the pandemic and said Hart’s arrival reminded her that life continued even during a difficult period.
She also said that raising a child made her feel more committed to creating a better world.
Hart Kail Loves Christmas Songs
Michelle shared a small detail about Hart during a November 2022 appearance on Live with Kelly and Ryan.
At the time, Hart was very interested in Christmas.
Michelle said he wanted to hear Christmas songs before bed and was trying to learn the names of Santa’s reindeer.
She said he was allowed three songs before bedtime, and he wanted all three to be Christmas carols.
It is one of the few personal details Michelle has publicly revealed about him.
Hart Kail Has Three Siblings
Hart is one of Michelle Williams’ four children.
He has:
- an older half-sister, Matilda Rose Ledger;
- a younger sibling born in 2022;
- a younger sister born in early 2025.
Hart is Michelle’s second child overall and Thomas Kail’s first child with Michelle.
Who Is Matilda Ledger?
Hart’s older half-sister is Matilda Rose Ledger.
She was born on October 28, 2005, in New York City.
Matilda’s parents are Michelle Williams and the late Australian actor Heath Ledger.
Michelle and Heath met while working on Brokeback Mountain. They later became a couple and welcomed Matilda.
They separated in 2007.
Heath died in January 2008 from an accidental drug overdose.
Hart and Matilda Have a Large Age Gap
Matilda is almost 15 years older than Hart.
Despite the age difference, reports indicate that she is close to her younger siblings.
After the family’s youngest child arrived in 2025, a source told PEOPLE that Matilda had been doting on her younger siblings.
Michelle has also spoken about Matilda introducing her younger siblings to some of her favorite Christmas movies.
Hart’s Younger Sibling Was Born in 2022
Michelle and Thomas welcomed another child in 2022.
The baby was their second child together and Michelle’s third overall.
The couple was seen walking in New York City with a newborn in October 2022.
They have not publicly revealed the child’s name in the available information.
Reports have also differed or remained unclear about the child’s sex, so it should not be stated as confirmed.
Hart’s Youngest Sister Was Born in 2025
Michelle and Thomas welcomed another child in early 2025 through surrogacy.
The baby’s arrival was reported in April 2025.
Michelle later confirmed during an August 2025 appearance on Jimmy Kimmel Live! that the child is a girl.
She also thanked their surrogate, Christine, for helping them welcome their daughter.
The girl’s name has not been publicly revealed.
Hart’s Connection to Heath Ledger
Hart is not biologically related to Heath Ledger.
Their family connection comes through Matilda.
Heath is Matilda’s father, while Thomas Kail is Hart’s father. Hart and Matilda share the same mother, Michelle Williams.
Heath died around 12 years before Hart was born.
The Family Enjoys Christmas Together
Michelle has shared a few details about Christmas with her children.
During her November 2022 television appearance, she said the family had watched White Christmas many times.
Matilda enjoyed those movies, and Michelle said she was excited for her to share them with the younger children.
At the same time, Hart was interested in Christmas songs and Santa’s reindeer.
Why Hart Kail Is Rarely Seen in Public
Michelle Williams has made privacy an important part of raising her children.
She followed a similar approach with Matilda, keeping her away from constant media attention while she was growing up.
Hart is also rarely seen at public events.
His parents have not shared regular photographs, school information, or detailed updates about his daily life.
As a result, most reliable information about Hart comes from the few comments Michelle has made during interviews.
Where Does Hart Kail Go to School?
Hart’s school has not been publicly identified.
There is no reliable public information about his current education.
His parents have kept these details private.
Does Hart Kail Have a Career?
Hart does not have a public career.
He is still a young child and is known because of his parents.
There is no reliable information showing that he works as a child actor, model, or performer.
Is Hart Kail on Social Media?
Hart does not have a known verified public social media account.
Any accounts using his name should not automatically be considered official.
Hart Kail’s Net Worth
Hart Kail’s personal net worth is not reliably known.
He is a child with no publicly documented professional income.
Online estimates of his parents’ wealth should not be presented as Hart’s personal net worth.
Facts About Hart Kail
- Hart Kail is the son of Michelle Williams and Thomas Kail.
- He was born in 2020.
- His birth month is widely reported as June.
- His exact birthday and birthplace have not been publicly confirmed.
- Hart was born during the COVID-19 pandemic.
- He is Michelle Williams’ second child.
- He is Michelle and Thomas Kail’s first child together.
- His parents met while working on Fosse/Verdon.
- Michelle and Thomas married in 2020.
- His father is known for directing Hamilton.
- His mother is known for projects including Brokeback Mountain, Blue Valentine, The Greatest Showman and The Fabelmans.
- Hart’s older half-sister is Matilda Rose Ledger.
- Matilda’s father was the late actor Heath Ledger.
- Hart also has two younger siblings.
- His youngest sibling is a girl born through surrogacy in early 2025.
- Michelle has said Hart loved Christmas songs as a young child.
- He was also interested in learning the names of Santa’s reindeer.
- His school has not been publicly identified.
- Hart has no known public career or verified social media account.
- His parents keep most details about his childhood private.
- His personal net worth is not reliably known.
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