Nelsons was born in Riga, Latvia, on November 18, 1978. His parents and stepfather were musicians, and at an early age, Nelsons studied piano but took up the trumpet at 12. He later sang in his mother's early music ensemble and played trumpet in the Latvian National Opera Orchestra. After local studies, Nelsons began studying conducting at the St. Petersburg Conservatory with Alexander Titov. In 2002, he began studying privately with famed conductor Mariss Jansons. Nelsons' orchestral repertory includes large portions of Mozart, Mahler, and Shostakovich. His operatic repertory takes in much Wagner and Puccini, as well as Bizet, Tchaikovsky, and Richard Strauss.
Nelsons has conducted around the globe, including throughout Europe, the U.S., and Japan. He served as principal conductor of the Latvian National Opera from 2003-2007. In 2006, he took on a second important post, this one as chief conductor of the Nordwestdeutsche Philharmonie, a position he held until 2009. From 2007, Nelsons began making regular appearances in the U.K., and that September was named music director of the City of Birmingham Symphony Orchestra, beginning in the 2008-2009 season. He held this post until the conclusion of the 2014-2015 season. 2009 saw Nelsons' debut at the Met, leading a performance of Puccini's Turandot. The following year, Nelsons made his debut at the Bayreuth Festival with a production of Wagner's Lohengrin; this followed a concert performance given in Birmingham with the City of Birmingham Symphony. In 2011, a highly praised reading of Mahler's Ninth Symphony at Carnegie Hall with the Boston Symphony Orchestra marked two more important debuts for Nelsons; this was his first performance at Carnegie Hall and his first time leading the Boston Symphony. Nelsons was named the Boston Symphony's 15th music director in 2014, after several years of guest conducting. In 2018, Nelsons was named the 21st Gewandhauskapellmeister (music director) of the Gewandhausorchester Leipzig.
Nelsons has an exclusive recording contract with the Deutsche Grammophon label but has also recorded for Decca and Orfeo, among others. He has continued to receive acclaim for his recordings, especially those of his continuing surveys of the symphonies of Shostakovich, with the Boston Symphony, and Bruckner (which is paired with music by Wagner), with the Gewandhausorchester Leipzig. In 2020, Nelsons received contract extensions with both groups: the Boston Symphony until 2025 and the Gewandhausorchester Leipzig until 2027. Nelsons led the Gewandhausorchester Leipzig on a recording of Bruckner's first and fifth symphonies with Wagner's Prelude and Liebestod from Tristan and Isolde in 2022. ~ Robert Cummings & Keith Finke, Rovi