"Lords of Summer" is a song by American heavy metal band Metallica. It was first released as a digital single in its demo form on March 19, 2014, with a 12-inch single for it being released as part of Record Store Day Black Friday later that year. In 2016, a re-recorded version was included on the deluxe edition of the band's tenth studio album, Hardwired... to Self-Destruct.

In February 2014, Metallica began recording a new song at their HQ studio in San Rafael, California, with the working title "X-Dust", planning to premiere it at a March 16, 2014, show in Bogotá, Colombia. They finished it in March and premiered it at the show with the official song title "Lords of Summer".^[1] The band re-recorded the song in May and June 2015 for their tenth studio album, Hardwired... to Self-Destruct (2016),^[1] including it with the deluxe edition of the album. It is over a minute shorter in length than the demo and first pass versions.^[2]

According to drummer Lars Ulrich, the song was inspired by the band's then upcoming 2014 tour, as he explained in an interview given to Metal Hammer magazine: "It's about being outdoors and festivals and here we are again."^[3] Being an uptempo thrash metal song much in the vein of Metallica's earlier works from the 1980s and being self-referential in nature in terms of its lyrical content, the song alludes to a number of now 'classic' tracks from that particular period, most notably "The Four Horsemen" and "No Remorse" (both from 'Kill 'em All', 1983): "Pounding, pounding, no remorse / Lords of summer set on course / Pushing, pushing horsemen ride / Lords of summer undenied".

The band released the song digitally through the iTunes Store on March 19, 2014, in its demo form.^[4] They eventually released the song in a more refined state, dubbed the "First Pass Version", digitally in June.^[5] Later that year, they gave the song a physical release for Record Store Day Black Friday as a 12-inch single, with a live version of the song recorded in Rome being used as the B-side. The single was limited to 4,000 copies.^[6] A remix of the song by The Glitch Mob was released on May 13, 2015, through YouTube.^[7]

• James Hetfield – vocals, rhythm guitar
• Kirk Hammett – lead guitar
• Robert Trujillo – bass guitar
• Lars Ulrich – drums