This study investigates the distributed control strategy for handling the time-invariant and time-varying formation tracking problem of a class of non-linear nonidentical leader–follower multi-agent systems with uncertainties and unknown external disturbances. Firstly, the neighbour-based distributed finite-time observers are proposed for the followers to estimate the position and velocity of the leader. Then, two novel distributed adaptive formation control algorithms based on the approximation capability of neural networks and sliding mode are developed. One can prove that, with the proposed observer and the control laws, all the followers will reach the desired time-invariant or time-varying formation tracking, and achieve the consistent velocity with the leader in spite of uncertainties and disturbances. Finally, illustrative simulation examples are given to verify the effectiveness of the obtained theoretical results.