Originally from South Australia, Alex Mitchell began violin lessons at the age of six. She gave her first recital at 11 while studying with Marie Roberts. When she was 14, she moved to Sydney to study with Alexandru Todicescu. She was subsequently appointed Concertmaster of the SBS Youth Orchestra, with whom she also appeared as a soloist and toured Europe and the UK. She made her first CD at 15 years of age for Youth Music Endeavours Ltd, playing Saint-Saëns' Introduction and Rondo Capriccioso. At 17 she won the National Youth Concerto Competition and became the youngest player to win a permanent position with the Australian Opera and Ballet Orchestra. In 2000 a Big Brother Scholarship enabled her to study in London with Emanuel Hurwitz, who then invited her to attend the Yellow Barn Music Festival in Vermont, USA.
In 2001 she won a Fellowship with the Sydney Symphony Orchestra and soon after was appointed to the First Violins. In 2005 and 2006 she was a string finalist in the Symphony Australia Young Performers Awards, performing Prokofiev's Violin Concerto No.1 and Shostakovich's Violin Concerto No.1.
In 2005 she performed Mendelssohn's Violin Concerto with the Eastern Sydney Chamber Orchestra and in 2006 she played Shostakovich's Violin Concerto No.1 with the Melbourne Symphony Orchestra in preparation for the orchestra's European tour in 2007. In 2008 she was invited to work as Concertmaster with the Australian Opera and Ballet Orchestra for their seasons of Carmen and Arabella.
Recently she has played in chamber music concerts with the Australia Ensemble, the Sydney Soloists, and the Sydney Omega Ensemble.
Alex Mitchell currently plays a 1932 Giuseppe Pedrazzini violin, lent to her by the Sydney Symphony Orchestra.