A collapsible cardboard cup, comprising a peripheral side wall with a circular upper edge which surrounds an upper opening, a multi-cornered lower edge with rectilinear sides (4.1 to 4.6) between the corners (6.1 to 6.6) which surrounds a lower opening, first vertical fold lines (7.1 to 7.4) starting from the corners (6.1, 6.3, 6.4, 6.6) and extending in the direction of the upper edge over part of the height of the side wall, two diametrically opposing second vertical fold lines (8.1, 8.2) which extend in each case from a corner (6.2, 6.5) on the lower edge vertically upwards to the upper edge of the side wall, and a bottom with at least one bottom wall which is connected via a first horizontal fold line to a rectilinear side (4.4) of the lower edge and at least one bottom flap holding the bottom wall in horizontal orientation in the lower opening, wherein the collapsible cup has lateral bottom flaps (20.1 to 20.4), which are connected via third horizontal fold lines (19.1, 19.2, 19.3, 19.4), on the lower edge on the rectilinear sides (4.2, 4.3, 4.5, 4.6) which are adjacent to the second vertical fold lines (8.1, 8.2), wherein one lateral bottom flap (20.1, 20.3) of two respectively adjacent lateral bottom flaps (20.1 to 20.4) is connected to a connecting flap (22.1, 22.2) via a diagonal fold line (21.1, 21.2) which is inclined at an angle of 45° to the third horizontal fold line, which connecting flap is adhesively bonded to the adjacent lateral bottom flap (20.2, 20.4), whereby the lateral bottom flaps (20.1 to 20.4) in the folded state are folded around the diagonal fold lines (21.1, 21.2) and in the erected state are folded into the lower opening around the third horizontal fold lines (19.1 to 19.4), characterized in that the lateral bottom flaps (20.2, 20.3) which are arranged adjacent to the first horizontal fold line have lugs (23.1, 23.2) which protrude on the sides facing one another adjacent to the third horizontal fold lines (19.2, 19.3) and which are arranged below the bottom wall in the erected state of the collapsible cup. the collapsible cup has lateral bottom flaps (20.1 to 20.4), which are connected via third horizontal fold lines (19.1, 19.2, 19.3, 19.4), on the lower edge on the rectilinear sides (4.2, 4.3, 4.5, 4.6) which are adjacent to the second vertical fold lines (8.1, 8.2), wherein one lateral bottom flap (20.1, 20.3) of two respectively adjacent lateral bottom flaps (20.1 to 20.4) is connected to a connecting flap (22.1, 22.2) via a diagonal fold line (21.1, 21.2) which is inclined at an angle of 45° to the third horizontal fold line, which connecting flap is adhesively bonded to the adjacent lateral bottom flap (20.2, 20.4), whereby the lateral bottom flaps (20.1 to 20.4) in the folded state are folded around the diagonal fold lines (21.1, 21.2) and in the erected state are folded into the lower opening around the third horizontal fold lines (19.1 to 19.4), characterized in that the lateral bottom flaps (20.2, 20.3) which are arranged adjacent to the first horizontal fold line have lugs (23.1, 23.2) which protrude on the sides facing one another adjacent to the third horizontal fold lines (19.2, 19.3) and which are arranged below the bottom wall in the erected state of the collapsible cup.