Eternal Nightcap is the third studio album by Australian rock band The Whitlams, first released by Black Yak Phantom in September 1997. The album peaked at number 14 on the ARIA charts and was certified gold, and then triple platinum.

Single No Aphrodisiac was voted number 1 on the Triple J Hottest 100 in January 1997 and won Song of the Year at the 12th Annual ARIA Music Awards in 1998. Eternal Nightcap won Best Independent Release, and The Whitlams won Best Group. The band toured in support of the album and played 150 dates on the Learning Your ABC's National Tour presented by Triple J, Recovery and Rage.

A limited edition vinyl LP of Eternal Nightcap was released in 2006, with only 500 copies being pressed. Notably, "Love is Everywhere" and "Tangled Up in Blue" were left off this version of the album.

On 6 August 2009, The Whitlams played Eternal Nightcap in its entirety for the first time, with the exclusion of "Tangled up in Blue", at the Karova Lounge in Ballarat. In August 2009, they played the entire album in full before moving on to various other hits, first at The Corner Hotel in Victoria and then at the Tivoli in Brisbane.

In September 2022 the band played a national tour "Eternal Nightcap 25 Years" and released a remastered version of the Eternal Nightcap album. The 2022 re-release was baked and extracted from original 1/2 inch tapes. The 2022 vinyl release of the album included all tracks except 'Life's a Beach'.