Now That's What I Call Music! 78 (UK series)

Now That's What I Call Music! 78 or Now! 78 is a double-disc compilation album that was released in the United Kingdom on 11 April 2011 on CD and downloadable formats. The album is the 78th edition of the UK Now! series.

Now 78 features six songs which reached number one on the UK Singles Chart: "Grenade", "We R Who We R", "When We Collide", "Price Tag", "What's My Name?", and "The Time (Dirty Bit)".

The version of Jessie J's song "Price Tag" is the solo version, instead of the version featuring B.o.B which reached number one and also, the version of Taio Cruz's song "Higher" is the US version which features Travie McCoy instead of the UK version which features Kylie Minogue.