"On 1st January 1998 the people of Bengal started Trinamool meaning grassroots. Today we are 18 always with the people, for the people, by the people," Banerjee said in a statement.
She also wished the people of the state in the new year. "Today I complete my first year on Twitter. Enjoying digital journey with you all on Twitter and Facebook. Stay happy and healthy in 2016. Happy New Year."
TMC's foundation day was celebrated across the state with small street corner meetings and flag hoisting programs at various parts of the state.
The TMC leaders in districts used the occasion to spread the report of development by the party pursued in the last four and a half years.
Trinamool Congress was formed by Banerjee on Januaray 1, 1998 with an aim to oust the then Left Front regime from power.
The party achieved its goal in May 2011, when the TMC forging an alliance with the Congress dislodged the 35-year old Left regime from the state.