Actor and director Simon Baker learns about a legacy left by his three-times great grandfather, and the substantial courage and fortitude of his female ancestors.

Bad boy larrikin actor Ben Mendelsohn embarks on a journey into his ancestry to find out if he really is related to the famous composer of the Wedding March - Felix Mendelssohn. He traces the Mendelsohn family line back to the heart of Europe and discovers a thread of musical heritage in surprising quarters as well as a heart-rending tale of success, failure and heartbreak of Dickensian proportions.

Actor David Wenham rose to fame as ‘Diver Dan’ in the long-running TV series SeaChange. He has inhabited countless characters in a 30-year career spanning theatre, TV and film but the characters in David’s own bloodline remain largely unknown to him.

Rebecca Gibney attempts to find out more about her past and travels to New Zealand. The journey takes her from Parihaka to Wellington to Auckland, where she learns some shocking truths about her family history.

Actor, former self-described 'serial pest', and member of the Stolen Generation, Uncle Jack Charles has never known the love of a parent. He will uncover details of the father he never knew.

Singer Tina Arena has always wanted to find out more about where her Italian-born parents came from, a subject that has never really been talked about in her family. She is driven to find out the truth behind some family secrets and heads off to Sicily to explore her Italian roots and the tough reality of her grandparents’ childhoods.

Amanda Keller finds out that her bloodline has survived against all odds as she discovers that an ancestor faced hell on earth in Australia‟s most brutal prison and a mother who saved her family in the face of tragedy.

Jeff Fatt, famous as the Purple Wiggle, knows his Chinese roots go back four generations into Australia's history, but he wants details of why those ancestors came to Australia.

Catherine Freeman represented her people and her country as an athlete and, on the most memorable night in Australian sporting history, won a gold medal at the Sydney 2000 Olympic Games. In her own words, she “runned fast”. Earlier, she’d lit the Olympic Flame in the Opening Ceremony, making her the first person to light the Olympic flame and win a gold medal at the same games. Catherine believes that your make-up is a product of the past, so it’s natural for her to want to find out about her ancestors. She’s interested in finding out from where she inherited her athletic ability. Catherine also believes you inherit your emotions and psychology from your ancestors and she’s extremely curious to discover what aspects of her innate nature are also inherited. She hopes that learning about her ancestors will make her feel more at ease with who she is, and stronger going into the future.

Internationally celebrated actor Geoffrey Rush believes he hails from a long line of farmers but an exploration of his heritage sees him discover an ancestor fighting for justice in the face of corruption and another desperate to succeed in a golden age of creativity.

Sporting legend Dawn Fraser is a hands-on grandmother who wants to know more about her own grandparents. This Aussie icon discovers she has South American heritage.

Having always struggled to understand culturally who he is, renowned neurosurgeon Charlie Teo is looking for answers. Exploring his mother’s side of the family, Charlie’s journey will take him to Malacca, where he discovers a culture he’s never heard of, but one with which he can now clearly identify. On his father’s side, Charlie comes face to face with his paternal ancestors. Will he be able to mend his connection with this side of his family and finally be proud of his Teo heritage?

Singer Christine Anu's ancestry is from the Torres Straits Islands. She’d like to understand why music is so important in her life. Her journey takes her not only to the Torres Straits but to England where she discovers a heritage of music and culture, beyond her wildest dreams.

Rock star and activist John Butler is searching for his heritage hoping to find poets, musicians and revolutionaries. In his WDYTYA journey John traces the Butler name back through generations of hardship to a matriarch who sang for her survival. Then he follows his Bulgarian ancestry to the mountain town of Koprivshtitsa and to an ancestor caught up in a violent revolt, central to the birth of a nation.

Footy legend and latter day ‘Knight in Shining Armour’ Ron Barassi has always believed that actions speak louder than words. He embarks on a journey into his ancestry tracing the Barassi family line back to the Victorian Gold Rush and discovers a heart-rending tale of violence, tragedy and redemption.

Iconic entertainer Greig Pickhaver, known for his comedic alter ego HG Nelson, investigates the leading characters in his family history. His search uncovers a great-grandfather, Samuel Rinder, who in the late 19th century, made his fortune as a sheep trader during Bendigo’s boom years. As a wealthy man about town, Rinder spent much of his time and money down at the racetrack, but when economic recession loomed, he turned to crime.

Traumatised by the scandal of her parents' public divorce, investigative journalist, Jennifer Byrne, has avoided examining her family history until now, when both her parents have passed away.

Actor Toni Collette delves into the enigma of her grandparents and uncovers a tale of abandonment and tragedy, a secret wartime affair, and an unexpected ancestor. A DNA test serves only to deepen the mystery.

Successful Chef and Restaurateur, Luke Nguyen discovers his Grandfather had a wife and child in China, who he left behind, when he migrated to Vietnam and began a second family. Luke searches a remote corner of China to bring this long lost family back into the fold. He then travels to Vietnam and looks into the troubled history of his parents’ homeland, searching for clues to explain his own painful past.

Singer-songwriter Delta Goodrem has searched for the creative connection in her ancestry - some link that would explain her own abilities. Her infectious curiosity is rewarded by the intricate adventures of her great grandmother, an enigmatic woman whose life took some unexpected twists and turns. As family secrets are revealed, Delta unveils her spirited great grandmother's passions in marvellous Melbourne.

Jack Thompson looms large in the Australian imagination from such iconic films as Breaker Morant and The Man from Snowy River. Born John Hadley Pain in Sydney in 1940, he knows very little about the history of his biological family. When his mother died, Jack was sent to a local boarding school as their father Harold was unable to look after them. Eventually Jack was adopted by the Thompson family and he took their name. For the first time, Jack Thompson, legend of the Australian screen, discovers the history of his biological relations and the importance of us knowing our own stories.

Dennis Cometti is the best known and most authoritative Australian Rules football commentator in Australia. Millions of football fans around the nation admire and respect his droll, quirky commentary. He knows everything there is to know about the genealogy of the AFL, confidently recalling any player’s pedigree, background and performance statistics – he spends hours researching the history of the game. But ask the ‘footy statistic guru’ about his own family and it is an entirely different story. He claims he has never had time to look into his own history. Dennis wants to reconnect with his Italian identity. Everyone else identifies with him being Italian and he’s bemused because he doesn’t - he can’t even speak the language. Who Do You Think You Are?® takes Dennis on a journey to explore his rich Italian heritage.

Ita Buttrose is a trail-blazer – the first female editor of a major newspaper in Australia, a publisher, broadcaster and campaigner of equal opportunity for women. She’s promoted health issues, the needs of family and Australia’s ageing population. She’s always had a passionate interest in her family’s history, particularly in trying to unravel why her family changed their name from Butters to Buttrose, but has never had the time to investigate. Driven by the fact that many of her immediate family have creative and “nomadic” lives, she’s curious to find out whether these are ancestral traits. Ita was made an Officer of the Order of Australia in 1988.

Australia's favourite scientist Dr Karl Kruszelnicki, is a qualified medical doctor, engineer, and physicist whose media career began in 1981.

When Celia Pacquola digs into her beloved mum's family, she finds her three times Scottish great grandfather, John Rae, was Sydney's first Town Clerk.