"Tomorrow Shall Be My Dancing Day" is an English carol usually attributed as 'traditional'; its first written appearance is in William B. Sandys' Christmas Carols Ancient and Modern of 1833. It is most well known in John Gardner's adaptation, but numerous other composers have made original settings of it or arranged the traditional tune including Gustav Holst, Igor Stravinsky and others. Several phrases and words in the carol suggest a pre-Reformation origin. There are no traceable sources predating Sandys' version. There was probably a dancing event associated with this that has been lost. The lyrics inspired Sydney Carter to compose "Lord of the Dance" following a similar pattern. It is included in The New Oxford Book of Carols (#132) where there are extensive notes.