The T Second Avenue Local is a prospective rapid transit service in the B Division of the New York City Subway. It is proposed to run on the Second Avenue Subway in Manhattan and its route symbol will be turquoise.

The Second Avenue Subway is a New York City Subway line that runs under Second Avenue on the East Side of Manhattan. The first phase of this new line, with three new stations on Manhattan's Upper East Side, opened on January 1, 2017. The full Second Avenue Line, if it will be funded, will be built in three more phases to eventually connect Harlem–125th Street in Harlem to Hanover Square in Lower Manhattan. The proposed full line would be 8.5 miles (13.7 km) and 16 stations long, serve a projected 560,000 daily riders, and cost more than $17 billion.