INDIGO, or IndIGO (Indian Initiative in Gravitational-wave Observations) is a consortium of Indian gravitational-wave physicists. This is an initiative to set up advanced experimental facilities for a multi-institutional observatory project in gravitational-wave astronomy. Since 2009, the IndIGO Consortium has been involved in constructing the Indian roadmap for gravitational-wave astronomy and a phased strategy towards Indian participation in realizing a gravitational-wave observatory in the Asia-Pacific region. IndIGO is the Indian partner (along with the LIGO Laboratory in USA) in planning the proposed LIGO-India project. LIGO-India is a proposed advanced gravitational-wave detector to be located in India, whose concept proposal is now under active consideration by the science funding agencies in India and USA.

IndiGo is an Indian Low-cost airline headquartered at Gurgaon, India. It is the largest airline in India in terms of passengers flown with market share of 36.5 s of September 2015. The airline offers more than 671 daily flights connecting to 39 destinations including 5 international destinations with its primary hub at Indira Gandhi International Airport, Delhi. It presently operates a fleet of 101 aircraft belonging to the Airbus A320 family. In 2014, IndiGo carried 21.4 million passengers in the domestic sector alone.

Indigo is a color that is traditionally regarded as a color on the visible spectrum, as well as one of the seven colors of the rainbow: the color between blue and violet. Although traditionally considered one of seven major spectral colors, sources differ as to its actual position in the electromagnetic spectrum. Indigo is a deep and bright color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine.

Índigo is the third studio album by the Portuguese pop singer Susana Félix.It was recorded in 2006 and released in that same year. The lead single of the album was "Flutuo", followed by "Concilios", "Lua Na Ponte", "Sou Eu" and "Fintar a Pulsação".