"I really didn't expect to win three and getting the album of the year was a big thing for me, so I feel like all the hard work pays off when you get acknowledgement like that," she said.
While Sande scooped the best album title for "Our Version of Events", Labrinth won the best song award for "Earthquake".
US soul singer Dionne Warwick, the guest of honour, was presented with a lifetime achievement award to celebrate her 50 years in the music business.
London artist Plan B won the best male act and best hip hop/grime prizes.
Trinidadian-born US rapper Nicki Minaj won the best international act award, while Jamaica's Sean Paul was awarded the best reggae title.
The MOBO Awards, co-founded by Kanya King, are now in their 17th year.
"Each year we're staggered by the calibre of the talent on display," King said.
"Tonight has been a night for not only homegrown talent such as Emeli Sande and Plan B, who we've championed from the beginning of their careers, but also less represented genres of music such as gospel, jazz and African which are equally important for MOBO."
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