Olivia Tennet (born 4 January 1991) is a New Zealand actress and dancer best known in her home country for her role as Tuesday Warner on the nightly medical drama Shortland Street, along with several roles in television and theatre. Outside of New Zealand, she is best known for her roles in The Lord of the Rings: The Two Towers (2002), Power Rangers RPM (2009), and the independent film Blood Punch (2013).

Tennet began taking dance lessons at the age of four years following her older sister into dance, eventually stumbling into acting three years later She made her first major television appearance in the fourth season of Xena: Warrior Princess as the runaway Princess Alesia in the episode "If The Shoe Fits...".

Eventually, Tennet made her way into films. She went on to win the "Best Juvenile Performer" award at the Nokia New Zealand Film and TV Awards in 2000, for her role as Nicole Mitchell in Kids World. She also appeared in Peter Jackson's film adaptation of J. R. R. Tolkien's The Lord of the Rings: The Two Towers as Freda, a young girl of Rohan. She then won "Best Actress" at the Drifting Clouds Short Film Festival for her outstanding performance in the short film Watermark, beating the other adult nominees. The film won "Best Film" at the same awards.

Following this, Tennet became part of the core cast for Maddigan's Quest (2006) as Lilith. She then appeared as Tuesday Warner on Shortland Street for 54 episodes during the 2007 and 2008 seasons. She later portrayed the role of teenage genius Dr. K on Power Rangers RPM, the seventeenth season of the Power Rangers series which premiered in March 2009.

Around this time, Tennet competed in the "Sheilah Winn Shakespeare Competition" with classmate Phoebe Mason (Epsom Girls Grammar School Drama Leader 2008) and did quite well, winning four of fifteen awards. The 5-minute performance included various scenes from Macbeth. Tennet and Mason won a trip to the Globe Theatre in London, July 2009, as part of the Young Shakespeare Company.

Since her appearance on Power Rangers RPM, Tennet has participated in various television shows and theatrical productions in New Zealand. She played the role of nurse Lynne in an Auckland Theatre Company production of Stepping Out in June 2010, followed by the role of the Siren Queen for the Wet Hot Beauties' water ballet show titled Sirens for the Auckland Fringe Festival in February 2011. She also helped choreograph the show.

Later on, Tennet made a television appearance in an episode of The Almighty Johnsons as Delphine in March 2011. She also took the stage as Emilia in Peach Theatre Company's production of Othello in July 2011. She then took on the role of Dorothy in a major theatrical production of The Wizard of Oz based on the 1987 musical produced by the Royal Shakespeare Company at the Civic Theatre in September 2011, earning positive reviews for her portrayal of the character.

Before leaving for the United States, she made an appearance on Underbelly NZ: Land of the Long Green Cloud as Julie Theilman, a courier working for Terry Clark of the Mr. Asia drug syndicate.