Written and first recorded by Mark James (1975).
Hit version by Elvis Presley (US #32/C&W #1 1976).
From the wiki: “‘Moody Blue’, made famous by Elvis Presley, was written and first recorded by Mark James who also penned Elvis’ ‘Suspicious Minds‘. ‘Moody Blue’ was Presley’s last #1 hit in his lifetime, topping the Billboard magazine Hot Country Singles chart in February 1977.
“Presley recorded his version in February 1976, in the Jungle Room of his Graceland home. The only time Elvis performed the song in its entirety was on February 21, 1977 at a concert in Charlotte, North Carolina. He had attempted to perform the song February 20 at the same venue but revealed to the crowd that he had completely forgotten the lyrics; he returned on February 21, lead sheet in hand, and performed the song with his eyes glued to the lyrics.”
Elvis Presley, “Moody Blue” (1976):