Born in 1987 in Georgia, Buniatishvili began studying the piano under her mother at the age of three. She gave her first concert with the Tbilisi Chamber Orchestra when she was six years old, and appeared internationally at age 10. She studied in Tbilisi with Tengiz Amiredjibi, and in Vienna with Oleg Maisenberg. She speaks five languages fluently: Georgian, French, English, German, and Russian.
In 2006, Khatia was awarded a Special Award of the Tbilisi City Hall for artistry at the Tbilisi International Piano Competition.
Buniatishvili made her U.S. debut at Carnegie Hall in 2008. Since then, she has performed at the Hollywood Bowl, iTunes Festival, BBC Proms, Salzburg Festival, Verbier Festival, Menuhin Festival Gstaad, Festival de La Roque-d'Anthéron, Klavier-Festival Ruhr, and Progetto Martha Argerich. The venues she has performed at include: Walt Disney Concert Hall in Los Angeles, Royal Festival Hall in London, Musikverein and Konzerthaus in Vienna, Concertgebouw in Amsterdam, Berlin Philharmonie, Théâtre des Champs-Élysées, La Scala in Milan, Teatro La Fenice in Venice, Palau de la Música Catalana in Barcelona, Victoria Hall in Geneva, Tonhalle in Zurich, Rudolfinum in Prague, Grand Theater in Shanghai, National Centre for the Performing Arts in Beijing, National Centre for the Performing Arts in Mumbai, Suntory Hall in Tokyo, Esplanade Theatre in Singapore, and National Theater & Concert Hall in Taipei.
Buniatishvili's musical partners have included conductors such as Zubin Mehta, Placido Domingo, Kent Nagano, Neeme Järvi, Paavo Järvi, Mikhail Pletnev, Vladimir Ashkenazy, Semyon Bychkov, Myung-Whun Chung, and Phillipe Jordan. She has performed with the Israel Philharmonic, Los Angeles Philharmonic, San Francisco Symphony, Seattle Symphony, Philadelphia Orchestra, Toronto Symphony, São Paulo State Symphony, China Philharmonic, NHK Symphony, London Symphony Orchestra, BBC Symphony Orchestra, Orchestre de Paris, Orchestre National de France, Filarmonica della Scala, Vienna Symphony, Rotterdam Philharmonic, and the Munich Philharmonic.
Buniatishvili signed with Sony Classical as an exclusive artist in 2010. Her 2011 debut album included Liszt’s Sonata in B minor, Liebestraum No. 3, and Mephisto Waltz No. 1.
In 2012, Buniatishvili released her second album, Chopin, which featured solo piano works as well as Chopin's Piano Concerto No. 2 in F minor accompanied by the Orchestre de Paris and Paavo Järvi. The Guardian reported, "This is playing straight from the heart from one of today's most exciting and technically gifted young pianists".
In 2014, Buniatishvili released her third album, Motherland. An assortment of personally significant pieces, it included music from her homeland of Georgia.
Her fourth album, Kaleidoscope, was released on 5 February 2016. It featured Modest Mussorgsky's Pictures at an Exhibition, Maurice Ravel's La valse, and Igor Stravinsky's piano suite Trois mouvements de Petrouchka.
Her fifth album, Rachmaninoff, was released on 10 March 2017. It included Rachmaninoff's Piano Concerto No. 2 in C minor and his Piano Concerto No. 3 in D minor with the Czech Philharmonic Orchestra, conducted by Paavo Järvi (Sony Classical).
In 2015, Buniatishvili collaborated with rock group Coldplay for their album A Head Full Of Dreams.
She is a two-time ECHO Klassik Award winner.