The Symphony No. 1 in D minor is a symphony composed by Havergal Brian between 1919 and 1927. At around 105 minutes it is among the longest symphonies ever composed. Along with choral symphonies such as Beethoven's Ninth Symphony or Mahler's Eighth Symphony, it is one of a few works attempting to use the musically gigantic to address the spiritual concerns of humanity. Beginning in D minor and closing in E major, the work is an example of progressive tonality.

William Havergal Brian was a prominent 20th-century English composer, librettist, and church organist.