An engine fuel injection control apparatus is configured to alleviate the torque fluctuation that occurs due to deviation of the fuel injection timing from the optimum value when the excess air ratio is changed suddenly from lean to rich, such as when a NOx trapping catalytic converter is subjected to desorption and deoxidation treatment. When the excess air ratio changes by a large amount, the fuel injection timing is adjusted so as to change in accordance with the actual excess air ratio by executing an interpolation calculation based on the target excess air ratio and the actual excess air ratio. During the transient period when the actual excess air ratio is converging toward the target excess air ratio, the fuel injection timing is changed in accordance with the change in the actual excess air ratio and can therefore be set appropriately in relation to the actual excess air ratio. As a result, it is possible to alleviate torque fluctuation by suppressing the effect of the fuel injection timing to change rapidly in a step-like manner between target values before and after the excess air ratio changes.