In this study, we consider K n := circ (GN 1 , GN 2 ,. .. , GN n) circulant matrices whose entries are the Gaussian Nickel Fibonacci numbers GN 1 , GN 2 ,. .. , GN n. Then, we compute determinants of K n by exploiting Chebyshev polynomials of the second kind. Moreover, we obtain Cassini's identity and the D'Ocagne identity for the Gaussian Nickel Fibonacci numbers.