The United Kingdom was represented at the Eurovision Song Contest 1978 with the song "The Bad Old Days", written by Stephanie de Sykes and Stuart Slater, and performed by the band Co-Co. The British participating broadcaster, the British Broadcasting Corporation (BBC), selected its entry through a national final.
Before Eurovision
A Song for Europe 1978
The national final was held on Friday 31 March 1978 at the Royal Albert Hall, presented by Terry Wogan. The songs were backed by the Alyn Ainsworth Orchestra.
{| class="sortable wikitable plainrowheaders" style="margin: 1em auto 1em auto; text-align:center"
|+ A Song for Europe 197831 March 1978
|-
! scope="col" |
! scope="col" | Artist
! scope="col" | Song
! scope="col" class="unsortable" | Songwriter(s)
! scope="col" class="unsortable" | Points
! scope="col" | Place
|-
! scope="row" style="text-align:center;" | 1
| align="left" | Christian
| align="left" | "Shine It On"
| align="left" |
| 114
| 3
|-
! scope="row" style="text-align:center;" | 2
| align="left" | Brown Sugar
| align="left" | "Oh No, Look What You've Done"
| align="left" |
| 49
| 11
|-
! scope="row" style="text-align:center;" | 3
| align="left" | Fruit Eating Bears
| align="left" | "Door in My Face"
| align="left" |
| 49
| 11
|-
! scope="row" style="text-align:center;" | 4
| align="left" | Jacquie Sullivan
| align="left" | "Moments"
| align="left" | Jacquie Sullivan
| 106
| 6
|-
! scope="row" style="text-align:center;" | 5
| align="left" | Sunshine
| align="left" | "Too Much in Love"
| align="left" |
| 81
| 8
|-
! scope="row" style="text-align:center;" | 6
| align="left" | Ronnie France
| align="left" | "Lonely Nights"
| align="left" | Paul Curtis
| 68
| 9
|-
! scope="row" style="text-align:center;" | 7
| align="left" | The Jarvis Brothers
| align="left" | "One Glance"
| align="left" | Paul Curtis
| 114
| 3
|- style="font-weight:bold; background:gold;"
! scope="row" style="text-align:center;" | 8
| align="left" | Co-Co
| align="left" | "The Bad Old Days"
| align="left" |
| 135
| 1
|-
! scope="row" style="text-align:center;" | 9
| align="left" | Bob James
| align="left" | "We Got It Bad"
| align="left" |
| 66
| 10
|-
! scope="row" style="text-align:center;" | 10
| align="left" | Midnight
| align="left" | "Don't Bother to Knock"
| align="left" |
| 116
| 2
|-
! scope="row" style="text-align:center;" | 11
| align="left" | Babe Rainbow
| align="left" | "Don't Let Me Stand in Your Way"
| align="left" |
| 84
| 7
|-
! scope="row" style="text-align:center;" | 12
| align="left" | Labi Siffre
| align="left" | "Solid Love"
| align="left" | Labi Siffre
| 110
| 5
|}
Both groups Co-Co and Sunshine had participated in ', albeit with different line-ups. Co-Co would return to ' with another line-up, under the name The Main Event. Co-Co's member Cheryl Baker would eventually win the Eurovision Song Contest 1981 with the group Bucks Fizz.
{| class="wikitable plainrowheaders" style="margin: 1em auto 1em auto; text-align:center;"
|-
|+ Regional jury votes and on radio stations BBC Radio 1 and BBC Radio 2, with commentary by Ray Moore. The contest was watched by 21 million viewers.
The BBC appointed Colin Berry as its spokesperson to announce the British jury results.
Voting
{| class="wikitable"
|-
|+ Points awarded to the United Kingdom
|-
! scope="col" width="20%" | Score
! scope="col" | Country
|-
! scope="row" | 12 points
|
|-
! scope="row" | 10 points
|
|-
! scope="row" | 8 points
|
|-
! scope="row" | 7 points
|
|-
! scope="row" | 6 points
|
|-
! scope="row" | 5 points
|
|-
! scope="row" | 4 points
|
|-
! scope="row" | 3 points
|
|-
! scope="row" | 2 points
|
|-
! scope="row" | 1 point
|
|}
{| class="wikitable"
|-
|+ Points awarded by the United Kingdom