Thaddeus Rowe Luckinbill (born April 24, 1975) is an American actor and producer best known for playing J.T. Hellstrom on the CBS soap opera The Young and the Restless, from August 1999 to November 2010. He reprised the role of J.T. from December 2017 to April 2018, again in March 2019, and again in May 2023.

Thad Luckinbill has an identical twin brother, Trent, who is 12 minutes his junior. Trent Luckinbill is a lawyer who lives in Los Angeles.^[1] In the final episode of the television series Law & Order: Criminal Intent, "To the Boy in the Blue Knit Cap", Trent briefly appeared as the identical twin murder victim/corpse lying beside the murder victim/corpse of the character played by Thad.

Luckinbill married Young and the Restless co-star Amelia Heinle in March 2007 while their characters were also married on the show. He is stepfather to Heinle's son, August, from her previous marriage to Michael Weatherly. Their first child together, a son, Thaddeus Rowe, was born on November 2, 2007.[5] Their second child, a daughter, Georgia March, was born on December 17, 2009.^[2][3][4] On March 1, 2017, Luckinbill filed for divorce from Heinle, citing "irreconcilable differences". However, as of late 2019, they are not divorced.^[5]

Luckinbill enjoys playing volleyball, surfing, boxing and going to the gym.^[1] He occasionally plays for the Hollywood Knights basketball team.^[6] He majored in business finance at the University of Oklahoma.^[1]

Luckinbill is a cousin of fellow actor Laurence Luckinbill -- the son-in-law of comedienne Lucille Ball and husband to entertainer Luci Arnaz, and^[7] more distantly related to film directors Lana and Lilly Wachowski.

In 2013, Thad, with his twin brother Trent, and producer Molly Smith (producer of P.S. I Love You and The Blind Side) started a production company called Black Label Media. The production company has worked with A-listers such as Reese Witherspoon, Emily Blunt, and Jake Gyllenhaal, producing films including Sicario starring Blunt, Josh Brolin, and Benicio Del Toro, The Good Lie starring Witherspoon, and Demolition starring Gyllenhaal, Naomi Watts, and Chris Cooper.

In 2023 both Thad and Trent Luckinbill produced critically acclaimed film Reptile, teaming up once again with lead actor Benicio Del Toro. Thad also plays the character of ‘Peter’, a home contractor, in the movie, alongside Justin Timberlake and Alicia Silverstone.

On October 10, 2023, Reptile earned the #1 spot for English language films around the world on Netflix with 19.9 million views for the week. That being its second week in a row as the #1 most viewed English language film globally on Netflix.