Bandt was born the eldest of five children in the South Australian town of Moonta. The family moved to Adelaide after World War I, and in 1924 he began a fitting and turning apprenticeship with Duncan & Fraser Ltd who specialised in modifying Model T Fords.
He moved to Victoria in 1927 and Melbourne Motor Body & Assembling Company, and in 1929 he moved to the Ford factory as the subsidiary's first designer.
The design of the ute was a result of a 1932 letter from an unnamed Victorian farmer's wife asking for "a vehicle to go to church in on a Sunday and which can carry our pigs to market on Mondays". In response, Bandt developed the ute and the model called a "coupe utility" at the time was released in 1934. When the Australian version was displayed in the US, Henry Ford nicknamed it the "Kangaroo Chaser". A convertible version, known as the roadster utility was produced in limited numbers by Ford in the 1930s.
During World War II, Bandt helped to design long-range fuel tanks for Spitfire and Thunderbolt fighter planes. He also worked on design innovations for the UK-sourced Ford Zephyr, the 1967 Australian Ford Fairlane, and the never-approved Falcon convertible, of which six were built outside Ford in 1962.
Bandt married Nellie Rowe on 6 September 1941. He was a lifelong member of the Methodist (later Uniting) Church. He was known for his charity work. Lewis and Nellie had three daughters; Sylvia, Val and Ros. Later in life he also had four grandchildren; Brad, Tate, Eden and Joe. He was accomplished artist, and painted Ford’s nativity scene at Christmas. He retired in 1975.
Bandt was killed on 18 March 1987, while coming home from the Australian Broadcasting Corporation television studios where he had been recording a documentary about the ute. He was driving a 1934 model home when he collided with a truck near Bannockburn. He was survived by his wife and three daughters.
In 2008, the Lewis Bandt Bridge was opened and named in his honour.
- Warner, Gary (8 August 1999). "Who built the first utility - where - when". Archived from the original on 29 May 2015. Retrieved 5 July 2015.
- Veltri, Damian (2007). "Bandt, Louis Thornett (Lewis) (1910–1987)". Volume 17, (MUP). Australian Dictionary of Biography. Retrieved 5 July 2015.
- "A Tribute to Influential Australian Christians". 2010. Retrieved 5 July 2015.