Sissy Theodosia Christidou (Greek: Σίσσυ Θεοδωσία Χρηστίδου; born September 12, 1980) is a Greek TV hostess, journalist, youtuber, actress and ex-fashion designer. After she finished her acting studies on Higher Drama School of Giorgos Theodosiadis, she made her television debut as TV hostess of TV 100 daytime talk show C Throu in 2001. Right after she decided to study journalism and mass media.

She gained fame as a co-host on different popular greek morning television shows as Beautiful World in the Morning (2005-2008), In a really good mood (2008-2011) and Breakfast ANT1 (2011-2012). In 2013 she entered fashion industry with her own fashion brand sissychristidou.com. In 2017 she made her own YouTube channel sharing different part of her life. In 2018 she came back on TV hosting her own weekeend morning television talk show Come one, Smile! with Sissy Christidou. From 2021 she hosts the weekend morning television talk show Smile Again with Sissy Christidou on MEGA.

Theodosia Christidou was born on 12 September 1980, in Thessaloniki, Thodoris Christidis, a bank employee, and Mina Christidou, a housewife. She has a younger brother, named Giannis.

She graduated the Music High School of Thessaloniki in 1998. After she finished school she started studying acting and theatre on Higher Drama School of Giorgos Theodosiadis in Thessaloniki from she graduated on 2001 to start her career as an actress.

After she finished her acting studies she started taking part on different castings as an actress but very soon she decided not to pursue a career. In September of 2001 she made her television debut as hostess of TV 100 daytime talk show C Throu next to Christina Kanataki. At the same time she was hosting a daytime show as a radio producer on ANT1 Radio Thessaloniki. The two shows run for only one season and stopped on summer of 2002.

In September of 2002 she moved to Athens where she started working as a bank employee in ABN AMRO Bank for 9 months while she started studying journalism and media on Lab of Journalism. Moreover she signed with Virgin FM hosting a daytime radio show every evening for two years. She also signed with an actors agency taking part in different popular television commercials and ads.

In 2003 she started working on television as a journalist on late night talk show of ALPHA Ola with Themos Anastasiadis. After a year on the team of the show, the host Themos Anastasiadis proposed her to be the new co-hostess for the season 2004/05 and she accepted.

On summer of 2005 she signed a contract with one of the biggest Greek television networks MEGA. There from September of the same year she was one of the co-hosts of Grigoris Arnaoutoglou on the morning television talk show Beautiful World in the Morning. In 2005 she also made an appearance as herself on the huge MEGA comedy hit In the Nick of Time as herself. She continued appearing on the morning show for two more seasons until the summer of 2008. In 2008 she also made her acting debut playing on the comedy of Vasilis Myrianthopoulos Just Broke Up portraying Betty.

Right after she signed with ALPHA for the weekend morning talk show In a really good mood as a co-host of Natalia Germanou. In 2009 she also started hosting the greek version of the reality show Farmer Wants a Wife, Farmer Wants a Wife Greece which run for two seasons on the prime-time slot of ALPHA. On summer of 2011 she concluded her contract with ALPHA and the weekend show after three years.^[1] Moreover she was cast to be the voice of the Greek version of Smurfette on The Smurfs.

In August of 2011 she signed a contract with ANT1 when the producers decided to launch new shows on their morning slots. From October 17 she started hosting the morning entertaining talk show Breakfast ANT1 alongside Christos Ferentinos. The show concluded on July 6, 2012 when the ANT1 network decided to annul the entertaining slot 10:00am-13:00pm. Then Christidou decided to pause her television career for a six years.

In 2013 she decided to enter the fashion industry, creating and launching her own fashion brand and e-shop sissychristidou.com. The type of it was casual or formal outfits and clothes for woman of every body type. In 2017 she decided to create her own YouTube channel, named Sissy Christidou, posting her first video on September 1. A few months later the channel gained more than 200,000 subscribers while the content she was usually creating was personal moments, family stories, beauty, nutrition and travelling. On June 3, 2018 she and her -then- husband Thodoris Marantinis launched a second YouTube channel, named Visit My Greece, from which they were presenting videos from their couple trips around the country. On June 27, 2018 Christidou and Marantinis performed as a duet on 2018 - MAD Video Music Awards on a new version of the song Taste the Feeling.

The same month was announced that she signed with OPEN, a new greek television network, for coming back on TV on the weekend program of the network.

On October 27, 2018 she made her television comeback after six years with her new morning entertaining talk show Come on, Smile! with Sissy Christidou on OPEN.^[2] The show focused mainly on celebrity news, gossip, hollywood news and guests. On November 8 she announched the closure of her fashion brand, e-shop and store as a result of lack of time after six years.^[3]

On January 2021 the content and the focus of her television show changed presenting more news coverage and issues about social changes as the start of MeToo movement in Greece. Suddenly the ratings were increased making Come on, Smile! with Sissy Christidou one of the most popular greek tv shows. On July 4 she announced on air that she stops her show and contract with OPEN after three years. Days after she signed with MEGA for a spin-off of her show.^[4]

On September 11, 2021 she launched her new morning show Smile Again with Sissy Christidou on the weekend program of MEGA. There she presents a infotainment talk show with news and guests that concern the public opinion throughout the week. Smile Again with Sissy Christidou is now running its fifth season on air.

In 2005, Christidou began dating the singer of Onirama, Thodoris Marantinis. On August 13, 2008, she gave birth to their first son, Philipos-Rafael and one year later, on August 16, 2009, they got married. On August 29, 2013, she gave birth to their second son, Michael-Aggelos. On April 23, 2019, Christidou and Marantinis announced that they were separating.