A stackable chair comprising a seat , a backrest , two adjacent side structures along a y-axis of the chair , including a first side structure (LR) and a second side structure (LL), each of the two side structures supporting the seat and the backrest and comprising: ▪ a front leg (PaR, PaL) and a rear leg (PdR, PdL) located behind the front leg (PaR, PaL) along an x-axis of the chair extending from the rear to the front and being perpendicular to the y-axis, ▪ an armrest (AR, AL) rectilinearly extending from a first curved part (CAR, CAL) to a second curved part (CDR, CDL), ▪ a rear post (MR, ML) rectilinearly extending from the second curved part (CDR, CDL) to the rear leg (PDR, PDL), the chair being assemblable in a row by nesting another chair identical to the chair inside the chair such that the armrest (AL) of the second side structure (LL) of the other chair extends between the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the chair , along the y-axis, and the front leg (PaL) of the second side structure (LL) of the other chair extends between the front leg (PaR) of the first side structure (LR) of the chair and the front leg (PaR) of the second side structure of the chair (LL), along the y-axis, the armrest (AR, AL) of each of the two side structures (LR, LL) extending backwards away from a first longitudinal vertical plane parallel to the x-axis and perpendicular to the y-axis and located between the armrests of the two side structures, such that, when the chair and the other chair are assembled in a row, the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the other chair each extend backwards away from a second longitudinal vertical plane located between the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the other chair . ▪ a front leg (PaR, PaL) and a rear leg (PdR, PdL) located behind the front leg (PaR, PaL) along an x-axis of the chair extending from the rear to the front and being perpendicular to the y-axis, ▪ an armrest (AR, AL) rectilinearly extending from a first curved part (CAR, CAL) to a second curved part (CDR, CDL), ▪ a rear post (MR, ML) rectilinearly extending from the second curved part (CDR, CDL) to the rear leg (PDR, PDL), the chair being assemblable in a row by nesting another chair identical to the chair inside the chair such that the armrest (AL) of the second side structure (LL) of the other chair extends between the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the chair , along the y-axis, and the front leg (PaL) of the second side structure (LL) of the other chair extends between the front leg (PaR) of the first side structure (LR) of the chair and the front leg (PaR) of the second side structure of the chair (LL), along the y-axis, the armrest (AR, AL) of each of the two side structures (LR, LL) extending backwards away from a first longitudinal vertical plane parallel to the x-axis and perpendicular to the y-axis and located between the armrests of the two side structures, such that, when the chair and the other chair are assembled in a row, the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the other chair each extend backwards away from a second longitudinal vertical plane located between the armrest (AR) of the first side structure (LR) of the chair and the armrest (AL) of the second side structure (LL) of the other chair . <EOS>