The Hostage of Zir is a science fiction novel written by L. Sprague de Camp, the seventh book of his Viagens Interplanetarias series and the fifth of its subseries of stories set on the fictional planet Krishna. Chronologically it is the third Krishna novel. It was first published in hardcover by Berkley/Putnam in 1977, and in paperback by Berkley Books in 1978. A new paperback edition was published by Ace Books in 1982 as part of the standard edition of the Krishna novels. An E-book edition was published by Gollancz's SF Gateway imprint on September 29, 2011 as part of a general release of de Camp's works in electronic form. The novel has also been translated into German and Czech.