Tszyu was born on November 2, 1994, in Sydney, New South Wales, the son of Kostya Tszyu, the Russian-born former undisputed light-welterweight world champion inducted into the International Boxing Hall of Fame in 2011, and Natasha Anikina (Wikipedia). As a child Tim gravitated toward gymnastics and representative-level soccer for St. George and Bankstown rather than boxing, only turning seriously to the sport that made his father famous as a teenager, after Kostya warned him it was “a tough industry” that demanded full commitment (ESPN).

Tszyu compiled a 33-1 amateur record before turning professional in December 2016, debuting with a unanimous decision win at Sydney Cricket Ground with his father working his corner (Wikipedia). He built his record through a string of regional belts, including the WBC-ABCO Continental, WBA Oceania interim, IBF Australasian and WBO Global light-middleweight titles, staying unbeaten through his first 20 professional fights by 2022 (ESPN). His August 2020 win over former WBO welterweight champion Jeff Horn, an eighth-round corner stoppage, was also the moment he first pushed publicly out of his father’s shadow, telling reporters afterward, “I just want to let everyone know my name is Tim — not the son” (ESPN).

On March 12, 2023, Tszyu won the WBO interim super welterweight title with a ninth-round TKO of former unified champion Tony Harrison at Qudos Bank Arena in Sydney, a homecoming title fight the New South Wales government promoted as proof the state was “the leading sports State of Australia” (NSW Government). He defended the interim title with a first-round knockout of Carlos Ocampo that June, and was elevated to full WBO champion after titleholder Jermell Charlo vacated to move up and fight Canelo Alvarez, before beating Brian Mendoza by unanimous decision in October 2023 to retain the belt (Wikipedia).

Tszyu carried a 24-0 record and the WBO title into a defense against Sebastian Fundora on March 30, 2024, at T-Mobile Arena in Las Vegas, a fight that ended in a split-decision loss and his first professional defeat (Wikipedia). He returned that October to challenge Bakhram Murtazaliev for the IBF super welterweight title in Orlando, Florida, but was dropped four times before the fight was stopped in the third round, saying afterward, “Every time I step into the ring, I’m willing to die in here. The better man won tonight” (ESPN). After rebuilding with wins over Joseph Spencer and Anthony Velazquez through 2025 and a rematch loss to Fundora that July, Tszyu moved up to middleweight, winning the vacant WBO international title against Denis Nurja in April 2026 before defeating former undisputed welterweight champion Errol Spence Jr. by unanimous decision on July 25, 2026, in Sydney, a result that prompted Spence to announce his retirement (Bleacher Report).

His March 2023 homecoming title fight against Harrison was promoted by the New South Wales government as evidence of the state’s standing as Australia’s premier sporting destination, reflecting Tszyu’s status as one of the country’s most bankable boxing draws (NSW Government). The July 2026 win over Spence headlined a Prime Video and DAZN pay-per-view built around a reported total event purse near $15 million, one of the largest cards Australian boxing has hosted, and cemented Tszyu’s status as a multi-division world title claimant despite the two 2024 defeats that briefly threatened to derail his career (Bleacher Report).

Tszyu has built a roster of mostly Australian sponsors, including Brisbane-based Hannay Criminal Defence, which signed on to support his title pursuit in 2020 as part of a track record of backing young Australian boxers that also included former WBO welterweight champion Jeff Horn (Hannay Lawyers). He also carries an official apparel and equipment relationship with Everlast, which sells a dedicated Tim Tszyu collection through its Australian retail arm, though neither side has disclosed the value of the arrangement (Everlast Australia).

Tszyu has no publicly documented company or ownership stake outside boxing; his commercial activity centers on fight purses, endorsement income and his family’s long-running boxing gym business in Sydney. He remains closely tied to the Tszyu Boxing Academy inside the Rockdale PCYC, the gym his father built and where Tim has also worked as a trainer alongside his own competitive career (Fight.com.au). No separate outside business venture, media company, or equity stake was found in the sourcing for this profile.

Tszyu has not publicly documented specific real estate holdings of his own, and his primary Sydney base remains tied to the family’s boxing operation rather than any disclosed personal property. The Tszyu family’s long-time home, a six-bedroom, eight-bathroom property in Carss Park with a tennis court and pool that Kostya and his wife built and later sold at auction, illustrates the family’s earlier wealth but predates Tim’s own career earnings (The Leader). Tim continues to train and coach out of the Tszyu Boxing Academy at the Rockdale PCYC, the same gym his father established, rather than any separately disclosed personal training facility (Fight.com.au).