"A Lovely Day Tomorrow" is a 2004 single by British Sea Power, only released to shops in the Czech Republic but available at certain shows and via mail order in the United Kingdom.

Both versions of the song feature lead vocals by Kateřina Winterová of Ecstasy of Saint Theresa.

The song deals with the assassination of Reinhard Heydrich by two Czechoslovak agents during World War II.

To celebrate the entry of Czech Republic into the European Union it was decided to put out this release as a limited edition of 1,942 copies (the year the operation took place).

It was written and performed in the 1940s by the Czech hitmakers of the swing era - R.A. Dvorsky and his Melody Boys.