505, previously known as 505 CST and Paramount, is a residential skyscraper in downtown Nashville, Tennessee, located at the intersection of Fifth Avenue and Church Street. 505 stands on the location originally intended for the cancelled Signature Tower. The 45-story building is 522 feet (159 m) tall and feature 403,000 sq ft (37,400 m) of floor space. 505 is the tallest building in Nashville based on occupied floors, and the third tallest overall behind the AT&T Building and the Four Seasons Hotel and Residences. It includes 500 apartment units ranging from under 400 sq ft (37 m) to more than 4,000 sq ft (370 m), with an option to later convert the top 175 units to condominiums. Other planned areas include three retail spaces including an 8,000 sq ft (740 m) ground-level restaurant, a 45,000 sq ft (4,200 m) amenity level, and 690 parking spaces. It is expected to cost US$169 million. The architect is Solomon Cordwell Buenz.

Preleasing opened in November 2016, with rents ranging from $1,500 to $6,300 per month (excluding penthouses). The building topped out on May 18, 2017, and opened to its first tenants on October 1, 2017 in advance of completion in January 2018. Initially, no sales are planned for 505. The investment and financing arrangements, including an investment from a real estate investment trust, do not allow for sales during construction.

505 was named Best New Skyscraper in the 2017 Nashville Scene "Best of Nashville" awards.

• List of tallest buildings in Nashville

• 505 Nashville official website
• Giarratana Development