Brothers Tim and Phil Hanseroth — collectively known as The Hanseroth Twins — are Grammy-winning American singer-songwriters, multi-instrumentalists, and producers best known as the longtime musical and songwriting partners of Brandi Carlile. Identical twins raised in Washington state, the duo first joined Carlile's band in the early 2000s and have served as her primary co-writers, harmony vocalists, and rhythm section across nearly every album of her career.

Their first major songwriting impact came as co-writers of "The Story," the title track of Brandi Carlile's 2007 breakout album. Across the subsequent Carlile catalog — Give Up the Ghost (2009), Bear Creek (2012), The Firewatcher's Daughter (2015), By the Way, I Forgive You (2018), and In These Silent Days (2021) — they co-wrote and performed on hit after hit, earning multiple Grammy Awards as both songwriters and instrumentalists.