Irish author Sally Rooney has won the Costa Novel Award for her book Normal People.
The 27-year-old becomes the youngest recipient of the coveted prize.
Her second book, after 2017's Conversations With Friends, is a coming-of-age love story which the judges said "would electrify any reader".
The awards are given out across five categories - novel, first novel, biography, poetry and children's book.
Stuart Turton takes the First Novel Award for his debut, The Seven Deaths Of Evelyn Hardcastle.
The crime novel has been sold in 20 territories to date and has been optioned for TV.
Oxford professor Bart van Es won the Biography prize for his memoir The Cut Out Girl, a moving story of war, families, loss, survival and friendship.
The Poetry Award went to Scottish poet JO Morgan for Assurances.
The book-length war poem was partly inspired by the writer's father, who was an RAF officer involved in maintaining Britain's airborne nuclear deterrent.
Hilary McKay won the Children's book accolade for The Skylarks' War.
The winning authors - who will each receive £5,000 - were selected from 641 entries and their books are now eligible for the top prize, the 2018 Costa Book of the Year.
The winner will be selected by a panel of judges chaired by BBC presenter and journalist Sophie Raworth with category judges Rachel Joyce, Sathnam Sanghera, Mimi Khalvati, Anita Sethi and Rick O'Shea, joined by actor Simon Williams, writer and broadcaster Kate Humble and Bake Off star Prue Leith.
Dominic Paul, Costa's managing director, said: "The Costa Book Awards are all about recognising and celebrating some of the hugely enjoyable books out there.
"This year's stellar collection of award-winning books highlight the exceptional talent of authors writing in the UK and Ireland today. Many congratulations to each of this year's Costa Award winners."
The winner of the Book of the Year award will be announced on January 29.
The winner of the Costa Short Story Award, now in its seventh year, is voted for by the public and will also be announced at the ceremony.
Voting is open until January 11, until which time the three shortlisted authors remain anonymous.
For additional information go to www.costa.co.uk/costa-book-awards.