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abstract: 'We study three dimensional $O(N)_k$ and $U(N)_k$ Chern-Simons theories coupled to a scalar field in the fundamental representation, in the large $N$ limit. For infinite $k$ this is just the singlet sector of the $O(N)$ ($U(N)$) vector model, which is conjectured to be dual to Vasiliev’s higher spin gravity theory on $AdS_4$. For large $k$ and $N$ we obtain a parity-breaking deformation of this theory, controlled by the ’t Hooft coupling $\lambda = 4 \pi N / k$. For infinite $N$ we argue (and show explicitly at two-loop order) that the theories with finite $\lambda$ are conformally invariant, and also have an exactly marginal $(\phi^2)^3$ deformation. For large but finite $N$ and small ’t Hooft coupling $\lambda$, we show that there is still a line of fixed points parameterized by the ’t Hooft coupling $\lambda$. We show that, at infinite $N$, the interacting non-parity-invariant theory with finite $\lambda$ has the same spectrum of primary operators as the free theory, consisting of an infinite tower of conserved higher-spin currents and a scalar operator with scaling dimension $\Delta=1$; however, the correlation functions of these operators do depend on $\lambda$. Our results suggest that there should exist a family of higher 