According to Colin Escott's 2004 book Hank Williams: A Biography, Williams was inspired to write the song when he found it[clarification needed] on a schedule of upcoming MGM releases. The song was recorded on August 30, 1949, at Herzog Studio in Cincinnati, Ohio. Williams is backed by members of the Pleasant Valley Boys – Zeke Turner (lead guitar), Jerry Byrd (steel guitar), and Louis Innis (rhythm guitar) – as well as Tommy Jackson (fiddle) and Ernie Newton (bass). As Escott observed, the plaintive despair in Williams's voice on the recording is echoed by the backing of the musicians:
Zeke Turner underpinned "I'm So Lonesome I Could Cry" with recurring figures on the bass strings of the electric guitar. A few weeks earlier, Turner had led the backing on the Delmore Brothers' recording of "Blues Stay Away From Me" using very similar licks... Jerry Byrd played a solo of unusual simplicity, paraphrasing the melody to haunting effect, subtly adjusting tone and volume. Hank sang with unshakable conviction.
The song was released as the B-side to the blues "My Bucket's Got a Hole in It" because up-tempo numbers were deemed more appropriate for the jukebox trade than melancholy ballads. The single reached number four on the country chart in 1949.
"I'm So Lonesome I Could Cry" has become closely identified with Williams's musical legacy and has been widely praised. In the 2003 documentary The Road to Nashville, singer k.d. lang stated, "I think 'I'm So Lonesome I Could Cry' is one of the most classic American songs ever written, truly. Beautiful song." In his autobiography, Bob Dylan recalled, "Even at a young age, I identified with him. I didn't have to experience anything that Hank did to know what he was singing about. I'd never heard a robin weep, but could imagine it and it made me sad." In its online biography of Williams, Rolling Stone notes,
In tracks like "I'm So Lonesome I Could Cry", Williams expressed intense, personal emotions with country's traditional plainspoken directness, a then-revolutionary approach that has come to define the genre through the works of subsequent artists from George Jones and Willie Nelson to Gram Parsons and Dwight Yoakam.
Rolling Stone ranked it number 111 on their list of the 500 Greatest Songs of All Time, the oldest song on the list, and number three on its 100 Greatest Country Songs of All Time.
Music journalist Chet Flippo and Kentucky historian W. Lynn Nickell have each claimed how 19-year-old Kentuckian Paul Gilley wrote the lyrics, then sold the song to Williams along with the rights, allowing Williams to take credit for it. They stated that Gilley also wrote the lyrics to "Cold, Cold Heart" and other songs before drowning at age 27. However, Williams said he wrote the song originally intending that the words be spoken, rather than sung, as he had done on several of his Luke the Drifter recordings.