The Tor Doubles were a series of three dozen paperback anthologies published monthly from 1988 to 1991, each volume including two stories ranging from novelette to novel length. The format was Dos-à-Dos, "back to back," with each story bound upside-down relative to the other, each side having its own front cover; the format had been used in the 1950s and '60s by Ace Books, mostly for original novels.

The Tor Doubles were mostly reprints, and included mostly novellas by well-known authors. Several selections were full-length, previously published novels: those listed in bold titles below, by Bishop, Brackett, Dickson, and Leiber. And a few were original novellas, those by Benford & Carter, Dann & Haldeman, Haber, Ing, Popkes, and Turtledove, where the source publication shown below in parens is the Tor Double itself.

The series abandoned the dos format with volume 24 (Williams/Zelazny). The volumes by Dickson and Leiber were techically omnibuses, not anthologies, since both works in each volume had been previously published as separate novels.

The 'volume' numbers shown below correspond to the Tor Double sequence. (Note that #30 is unnumbered both on the cover and copyright page, and #35 is misnumbered #31 on the copyright page.) The complete sequence is shown in order at the isfdb link below.