The Reason Tour (also known as the On a Mission Tour) was the third set of concerts performed by English singer Melanie C. The tour ran from 24 April until 17 December 2003.
On 9 May 2003, the Shepherd's Bush Empire concert was webcast on MelanieC.net, and has since then been uploaded to her YouTube channel. In November 2003, the Avo Session Basel concert was broadcast on 3sat.