In this paper, we present FastPlace 3.0 - an efficient and scalable multilevel quadratic placement algorithm for large-scale mixed-size designs. The main contributions of our work are: (1) A multilevel global placement framework, by incorporating a two-level clustering scheme within the flat analytical placer FastPlace (Viswanathan and Chu, 2005) and Viswanathan et al., 2006), (2) An efficient and improved iterative local refinement technique that can handle placement blockages and placement congestion constraints. (3) A congestion aware standard-cell legalization technique in the presence of blockages. On the ISPD-2005 placement benchmarks (Nam et al., 2005), our algorithm is 5.12times, 11.52times and 16.92times faster than mPL6, Capo10.2 and APlace2.0 respectively. In terms of wirelength, we are on average, 2% higher as compared to mPL6 and 9% and 3% better as compared to Capo10.2 and APlace2.0 respectively. We also achieve competitive results compared to a number of academic placers on the placement congestion constrained ISPD-2006 placement benchmarks (Nam, 2006).