An adjustable footrest assembly adapted to a car safety seat is provided. The car safety seat includes a seat body. The adjustable footrest assembly includes a footrest and two flexible connection structures. The two flexible connection structures are connected to two ends of the footrest. The footrest is adapted to be connected to the seat body through the two flexible connection structures, and a length of each of the flexible connection structures is adapted to be adjusted to change a distance between the footrest and the seat body. In addition, a car safety seat having the adjustable footrest assembly is also provided. |