List of failed Thor and Delta launches

This is a list of failed launches of rockets in the Thor and Delta rocket family.
The Thor and Delta family rockets have had 51 complete failures, 10 partial failures, and 1 partial success, for a total of 62 unsuccessful Thor and Delta family missions. Since it has had 768 launches, this gives it a reliability of 91.9%, which puts it within the average range for rockets that started around the space age.

Launch attempts

1957-1959

! Date/Time

! Rocket
! S/N
! Launch Site
! Payload
! Function
! Orbit
! Outcome
! Remarks
! colspan="9" |

1960-1969

!Date/Time

!Rocket
!S/N
!Launch Site
!Payload
!Function
!Orbit
!Outcome
!Remarks
09:14:38
! colspan="9" |

1970-1979

!Date/Time
!Rocket
!S/N
!Launch Site
!Payload
!Function
!Orbit
!Outcome
!Remarks
! colspan="9" |

1980-1989

!Date/Time
!Rocket
!S/N
!Launch Site
!Payload
!Function
!Orbit
!Outcome
!Remarks
! colspan="9" |

1990-1999

!Date / time
!Rocket
Configuration
!Launch site
!Payload
!Payload mass
!Orbit
!Customer
!Outcome
!Remarks
! colspan="9" |

Since 2000