Born in Sarajevo but raised in the United States, Miličević moved to Troy, Michigan, in the early 1980s, where he became active in the local heavy metal scene and played in a number of bands, co-founding Morphic.

Tomo Miličević was born on September 3, 1979, in Sarajevo, Bosnia and Herzegovina, then part of SFR Yugoslavia, to a Bosnian Croat family.

[3] He attended culinary school at Oakland Community College, becoming a certified executive and pastry chef, and worked in a number of restaurants in Metro Detroit.

[4] He graduated from Athens High School in Troy and then moved to Los Angeles, rejoining his siblings Ivana and Filip.

However, during this period, manager Arthur Spivak, who had previously met Miličević at a showcase concert with Morphic, told him about an audition for Thirty Seconds to Mars.

Miličević then decided to move to Los Angeles where he had a successful audition with Thirty Seconds to Mars, replacing guitarist Solon Bixler.

Fueled by the band's relentless touring and the mainstream success of the single "The Kill", the album received multiple certifications all over the world, including platinum in the United States, with a worldwide sales total of over four million.

[13] After nearly a year of legal battles, the band announced on April 28, 2009, that the suit had been settled following a defense based on the De Havilland Law.

After signing to Cherrytree Records, Levan released the EP Introducing the Dame (2013), which features a collaboration with Miličević, who wrote and produced a number of tracks.

[26] During his youth, he had been influenced by jazz and classical music, listening to performers such as Stéphane Grappelli, John McLaughlin, Paco de Lucía, and Al Di Meola.

[2][3] He developed his interest in guitar from the moment he was introduced to heavy metal music, becoming a devoted fan of bands such as Pantera, Metallica, and Slayer.

[4] He grew up listening to progressive rock and blues artists, citing Jimi Hendrix, Pink Floyd, and Led Zeppelin.

[30][31] Rod Lockwood from The Blade described his work as "propulsive and energetic, with a big, anthemic sound that draws on U2, The Cure, and classic rock for its aural infrastructure".

[6] Miličević experimented with different instruments and drew influences from a varied range of styles in Love, Lust, Faith and Dreams.

[35] In addition to the guitar and violin, Miličević is also a fluent player of bass instruments, keyboards and percussion, and supplies backing vocals during concerts.

[36] After living in Los Angeles for over a decade, Miličević came back to Michigan in August 2014, moving to Indian Village in Detroit with his wife.

[39] In June 2008, he joined Habitat for Humanity to work with Thirty Seconds to Mars on a home being repaired and renovated through the Greater Los Angeles Area's "A Brush With Kindness" programme.