The song was written by both Lamar and SZA, along with Ink and Sam Dew, while production was handled by Sounwave, Jack Antonoff, Ruchaun "Scott Bridgeway" Akers, Kamasi Washington, Matthew "M-Tech" Bernard and Roshwita "Rose Lilah" Bacha.
"Luther" is a "love ballad" accentuated by various string sections against 808 beats and hi-hats which was called a blend of contemporary R&B and hip-hop by Screen Rant.
[2][3] It features a sample of "If This World Were Mine", written by Marvin Gaye and performed by Luther Vandross and Cheryl Lynn, and builds on the song title from the very beginning.
[5] Writing for NME, Kyann-Sian Williams thought the song was yet another demonstration of the duo's "chart-topping chemistry" and praised their "debonair" take on a "traditional love ballad".
[7] In New Zealand, "Luther" debuted at number one on the Official Aotearoa Music Charts, marking Lamar's fourth overall number-one single in the country, and his second for 2024.