John Booker (1603–1667) was an English astrologer, respected in that career for over 30 years. In the 1640s he was appointed licenser of mathematical publications, and so in effect a censor of astrological works, for the Stationers' Company.
He was born at Manchester 23 March 1601 OS (equals April 3rd 1601); his nativity is among the Ashmolean manuscripts (AstroDienst). He was originally apprenticed to a haberdasher in London, and was subsequently a writing-master at Hadley[disambiguation needed] and clerk to two city magistrates.
The first number of his almanac, the Telescopium Uranium, was published in 1631. He almost immediately obtained a reputation from a prediction of the deaths of Gustavus Adolphus and Frederick V, Elector Palatine, founded on a solar eclipse. In 1640 William Lilly thought highly of him, but they quarrelled over Booker's actions as licenser. Booker also engaged in violent controversy with Sir George Wharton.
His Bloody Irish Almanack contains historical material on the Irish rebellion, and he is the author of Tractatus Paschalis, or a Discourse concerning the Holy Feast of Easter (1664).