Select one of the keywords
Contests for Adults For Younger Readers

After Midnight Authors Contest
Win a choice of romances (monthly).
And After the Fire Contest New contest
Win Lauren Belfer's excellent historical (ends May 31, US, 18+).
Before the Fall Contest
Win Noah Hawley's novel (ends May 24, US, 16+).
Behind Closed Doors Contest New contest
Win the book by B. A. Paris (ends May 26).
Berkley Jove Contests
Fill in the form to win from a selection of books (monthly).
Bookbitch Contests
Chances to win 8 autographed thrillers (ends May 31, 18+).
BookReporter Best Books for Dad 2016 New contest
Win 5 novels & dad-themed treats (ends Jun 20).
BookReporter Word of Mouth Contest New contest
Win Boar Island, The Fireman (ends May 27).
Criminal Element Sweepstakes
Win crime fiction (ongoing).
Crown Publishing Read It Forward
Chance to win books (ongoing, US, 18+).
Free Book Friday
Chance to win every Friday (weekly, US & Can).
Fresh Fiction Contests
Win a variety of books (ongoing).
A Game for All the Family Contest
Win Sophie Hannah's new novel (ends May 24, US, 16+).
Goodreads Giveaways
Win a variety of prerelease books.
Hachette Book Group USA Contests
Win a variety of books (ongoing).
History in Five Sweepstakes New contest
Win a hardcover or signed edition book (monthly, 18+).
James Patterson Contests New contest
Win Michael Bennett: Alert (ends Jun 1, US & Can, not Quebec, 13+).
Myshelf.com Contest
Win books and audiobooks (ongoing).
NAL Authors Contests
Win from a selection of books (ongoing).
The New Neighbor Contest New contest
Win Leah Stewart's novel (ends May 26).
OnceWritten Contests
Lots of books, various genres (ongoing).
Prime Crime Contests
Win a selection of mysteries (ongoing, US, 18+).
The Queen's Poisoner Contest New contest
Win Jeff Wheeler's 1st in a new fantasy series (ends May 31, US, 18+).
Random House Competitions
Win books, trips, much more (ongoing, UK, 13+).
Reader Views Contests
Win a variety of books (ongoing, US & Can, 18+).
Sounding Off on Audio Contest
Win Curious Charms of Arthur Pepper, Don't You Cry audiobooks (ends Jun 1).
St. Martin's Read It First
Sign up, chance to win books (ongoing).
Susan Elizabeth Phillips Contests
Win signed Dream a Little Dream (ends May 31).
Writerspace Contests
Win ebook readers, books, gift certificates, much more (ongoing).

For Younger Readers Contests for Adults
Epic Reads Contests New contest
Win ARCs of various YA novels (ends May 29).