Ernest Lawrence Thayer (/ˈθeɪər/; August 14, 1863 – August 21, 1940) was an American writer and poet who wrote the poem "Casey" (or "Casey at the Bat"), which is "the single most famous baseball poem ever written" according to the Baseball Almanac,[1] and "the nation’s best-known piece of comic verse—a ballad that began a native legend as colorful and permanent as that of Johnny Appleseed or Paul Bunyan".

[2] During my brief connection with the Examiner, I put out large quantities of nonsense, both prose and verse, sounding the whole newspaper gamut from advertisements to editorials.

Besides being a native of a town close to Boston, Thayer, as a San Francisco Examiner baseball reporter in the off-season of 1887–88, covered exhibition games featuring Kelly.

Team Sport's First Media Sensation and Baseball's Original Casey at the Bat, reprints a 1905 Thayer letter to a Baltimore scribe who was asking about the poem's roots.

During the mid-1890s, Thayer contributed several other comic poems for Hearst's newspaper New York Journal and then began overseeing his family's mills in Worcester full-time.

In a sweet, dulcet Harvard whisper he implored "Casey" to murder the umpire, and gave this cry of mass animal rage all the emphasis of a caterpillar wearing rubbers crawling on a velvet carpet.