The opening ceremony was also attended by Mr Venkaiah Naidu, minister for urban development and Mr Siddaramaiah, chief minister of Karnataka.
Construction began on Phase 1 in 2007 and public services started in 2011 with the opening of the MG Road - Baiyappanahalli section of the east-west Purple Line.
The first section of the north-south Green Line opened in February 2014. The two lines intersect at Majestic station.
The opening of the southern section of the Green Line takes the total length of the Green Line to 24.2km. Phase 1 has a total length of 42km with 41 stations, two depots, one Operational control centre and one back-up control centre.
Alstom was awarded a €114m contract by Bangalore Metro Rail (BMRCL) in 2009 for the design, manufacture, supply, installation, testing and commissioning of the train control and signalling and telecommunications systems on both lines.
The contract also included deployment of Alstom's Urbalis 200 automatic train control solution.