This chapter further addresses the control problems of strict feedback systems (SFSs) with increasing dimensions. Compared with the commonly-considered SFSs treated in Chap. 6, where the subsystems have the same dimension, the control of SFSs with increasing dimensions is much more challenging. As in Chap. 6, first-order, second-order, and mixed-order cases have been all considered. We first considered SFSs whose gain matrices \(G_{i}, i=1,2,\cdots ,n,\) are all constant matrices and then extended the results to the more general cases where the gains \(G_{i},\) \(i=1,2,\cdots ,n,\) are state-dependent matrix functions. A coordinate transformation has been introduced to obtain the high-order FAS (HOFAS) model. Based on the high-order FAS models, the exponentially stabilizing controllers have been directly given. Besides first-order SFSs, second- and high-order SFSs with increasing dimensions are parallelly considered.