Tm3+-doped calcium niobium gallium garnet (Tm:CNGG) single crystals have been successfully grown by the micro-pulling-down (μ-PD) method. The crystal structure, absorption spectra, fluorescence spectra and lifetimes of Tm:CNGG crystals were investigated. The absorption and emission bandwidths of Tm:CNGG crystals are larger than those of other Tm3+ doped garnet crystals, which will be beneficial for laser diode (LD) pumping and ultrashort pulse generation. Additionally, continuous wave (CW) laser operation around 2 μm was achieved in the 2.0 at.% Tm:CNGG crystal by LD pumping.