A cable cleat system that secures cables to a ladder rack. The cable cleat system includes a mounting bracket assembly with a bracket body and a floating support bracket slidably mounted to the bracket body. A metal locking tie is positioned between the floating support bracket and the mounting bracket assembly. The mounting bracket assembly is secured to a ladder rung of the ladder rack and the floating support bracket supports the cables secured to the ladder rack. The metal locking tie wraps around the cables supported by the floating support bracket. The floating support bracket and the metal locking tie slide along the bracket body for enabling thermal expansion and contraction of the cables secured to the ladder rack.