The 668-room Octavius Tower at Caesars Palace was scheduled to open Monday.
The hotel-casino began booking rooms for the tower in late last year. The opening gives Caesars Palace more than 3,960 rooms and suites.
Caesars Entertainment Corp. halted construction of the Octavius Tower more than three years ago when the economy tanked.
The exterior and interior shells for the 19-story tower were completed, but the rooms were only just recently finished.
The Octavius Tower is expected to be the last new hotel tower to open on the Strip for several years, though many companies, including MGM Resorts International and Caesars Entertainment, are remodeling various properties.