On Through the Night is the debut album by English rock band Def Leppard, released in 1980. It charted at #51 on the Billboard 200 and #15 on the UK Albums Chart. The album features re-recorded versions of "Rocks Off" and "Overture", tracks from the band's original independently released EP, The Def Leppard E.P. Other tracks are rerecorded versions of early demos, some of which appeared on the First Strike and Warchild bootlegs. The album was certified platinum by the RIAA on 9 May 1989.
"Rocks Off", "Wasted", "Rock Brigade" (b/w "When the Walls Came Tumbling Down") and "Hello America" were released as singles. However, the versions of "Rocks Off" and "Wasted" that appears on the singles is a different recording from that of the LP, as is its B-side, "Hello America". The album was produced by Tom Allom.
AllMusic's Steve Huey rated On Through the Night three-and-a-half out of five stars. He noted that it "established the band as one of the leading lights of the New Wave of British Heavy Metal." He also called it "a collection of working-class hard rock anthems informed by the big, glittering hooks of glam rock." Although he stated that "it may lack the detailed production and more pop-oriented songwriting of later efforts," but concluded that "some Leppard fans prefer this sound." A staff member at Sputnik Music rated the album three out of five points. He noted that the "middle-class common-man image" of the "New Wave of British Heavy Metal" movement "partially played a part in making Def Leppard one of [its] leaders". He also stated that the band's ambition "would never allow [them] to be tunnel-visioned", but he concluded that the album "can be categorized as a grower of an album since the more superficial elements that would appeal to the mainstream will initially distract some listeners from what is actually an incredibly tight musical and vocal performance."Rolling Stone's David Fricke found the album favourable, explaining that it "shows they not only respect their elders, they've taken cues from their New Wave peers, too." He also stated that "guitarists Pete Willis and Steve Clark shoot from the hip, packing their licks into tight, three-minute pop arrangements", and that lead singer Joe Elliot "wails wonderfully in a resonating tenor, fortified by backup harmonies and Tom Allom's battering-ram production." He concluded that the album "is awfully impressive for a band making its vinyl debut."