The foursome have become the first girl group in eight years to spend more than one week at number one.
After getting the awesome news, Perrie Edwards, Jesy Nelson, Jade Thirlwall and Leigh-Anne Pinnock emailed a message to their fans from their official Twitter account.
They tweeted: "WOW! TWO weeks at NUMBER 1! thank you so so so much to everyone who has supported #BlackMagic The Girls."
Little Mix (@LittleMix) July 24, 2015
The last girl band to achieve the same success was Sugababes with their single 'About You Now' in 2007.
'Black Magic' became Little Mix's third single to reach the number one chart spot last week.
Their first No.1 single was 'Cannonball' in 2011, followed by 'Wings' in 2012.
At the time they said: "THANK YOU to every person that has supported #BlackMagic and made it NUMBER 1 in the UK!!! BEYOND happy!! The Girls #BlackMagicNumberOne.
"In case you can't tell... we're pretty happy about being number 1 and the #GetWeirdTour! Thank you Mixers!The Girls."
The great news tops off an amazing week for the girls after Jesy Nelson became engaged to boyfriend Jake Roche.
Rixton frontman Jake dropped to one knee and popped the question at the Manchester Arena, the venue where they first met, while Ed Sheeran performed their favourite song in the background.
Congratulations all round!
10 reasons why Little Mix are brilliant role models:
Watch Little Mix's 'Black Magic' below:
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!