Géza Gábor was born in Székesfehérvár in 1972. After starting off by studying piano, he gained admission to the solo voice course at the Ferenc Liszt Academy of Music in 1991, where he graduated with honours in 1996 after studying under programme heads Zsolt Bende and Dénes Gulyás. He continued his studies in the opera department, earning his degree in 1998 under the guidance of Ádám Medveczky and Balázs Kovalik. After receiving his diploma, he found work in numerous minor roles at the Hungarian State Opera. In 1999, he signed with the National Theatre of Szeged, where he spent an extremely productive ten years. In 2009, he returned to the Opera House in the role of Baron Ochs (in Strauss's Der Rosenkavalier), and has been one of its most frequently engaged permanent guest artists ever since. With quite a wide repertoire ranging from the Baroque to contemporary composers, and from seria to buffa, he has appeared in numerous festivals both in Hungary and abroad. In 2007, he received great acclaim for his performance as Fasolt in the Wagner Days in Budapest Opera Festival at Müpa Budapest. He also enjoys singing in musicals, including the roles of Caiaphas (in Jesus Christ Superstar) and Molokov (Chess). In addition to his dramatic works, his repertoire of oratorios is quite broad, and he has sung most of the works that are most frequently performed in Hungary. During his Szeged years, he was twice awarded both the Dömötör Award and the Award of the Friends of the Opera. In 1997, the Association of Hungarian Composers awarded him the Artisjus Award for the popularisation of contemporary music.

His principal roles include Bluebeard (Bluebeard's Castle), Osmin (Die Entführung aus dem Serail), Bartolo and Basilio (Il barbiere di Siviglia), Leporello and the Commendatore (Don Giovanni), the Inquisitor (Don Carlos), Procida (I vespri siciliani), Sparafucile (Rigoletto), Colline (La bohème), Angelotti (Tosca), Pistola (Falstaff) Rocco (Fidelio), Timur (Turandot), Fasolt and Fafner (Das Rheingold), Hunding (Die Walküre), Stefano (Adès: The Tempest), King Baldemar (Tallér: Leander and Linseed).