The Kannada film, which starred a cast of non-professional actors, became the first Indian movie in eight years to be selected in competition at the festival.
It featured in the Concorso Cineasti del Presentesection at the festival, held from August 5 to 15, 2015.
"It has always been a dream of mine to capture a little piece of India's soul on film, and this was the attempt with Thithi.
The award was announced on Independence Day, which made the victory even more special for the film team. "Thithi" also received a standing ovation after its first screening at the festival.
The other Indian films that have been screened at the Locarno film festival in the past were films like "Lagaan", "Black Friday" and "Mr and Mrs Iyer".