A fishing seat box (1) comprises: a footplate (200), of substantially rectangular shape, comprising attachment means (201) for a first pair of support legs (202, 203) in a first portion of the footplate and a frame (100) comprising a support base (101) of substantially rectangular shape, comprising further attachment means (104) for a second pair of support legs (105, 106) in a rear portion of the support base, and a guide (108) for slidably receiving the footplate in a front portion of the support base, and a support structure (102) to which a seat (103) of the seat box is fastened or fastenable. The footplate is translatable on the guide in such a way that it can be placed, alternatively, in a retracted position and in an extended position in which the footplate is partially pulled out of the guide. The frame (100) further comprises a pair of transverse supports (110a, 110b) which extend transversely between the support structure (102) and the support base (101) and which are fastened in respective opposed portions (109, 111), one facing forwards and the other facing backwards relative to the support structure (102) and the support base (101), so as to support the support structure (102) in a position spaced apart vertically from the support base (101).
