Can the 2025 Land Rover Defender make a U-turn?

Yes. Fits a 40 ft street.

38ft curb to curb

Street width, feet

Street 40 feet curb to curb.

2025 Land Rover Defender 90 P300 S AWD. Top view, to scale.

2025 Land Rover Defender: turning circle by trim, 40 ft street
Trim	Circle, ft	Margin	One move
90 P300 S AWD	38	+2 ft	Yes
S	42.1	-2.1 ft	No
110 P300 S AWD	42.1	-2.1 ft	No
110 P400 S AWD	42.1	-2.1 ft	No
90 P400 X-Dynamic SE AWD	38	+2 ft	Yes
130 P300 S AWD	42.1	-2.1 ft	No
X-Dynamic SE	42.1	-2.1 ft	No
110 P400 X-Dynamic SE AWD	42.1	-2.1 ft	No
130 P400 S AWD	42.1	-2.1 ft	No
130 P400 X-Dynamic SE AWD	42.1	-2.1 ft	No
Sedona Red	42.1	-2.1 ft	No
110 P400 Sedona Red Edition AWD	42.1	-2.1 ft	No
2025 Land Rover Defender 110 P400 Sedona Red AWD	42.1	-2.1 ft	No
130 P400 Outbound AWD	42.1	-2.1 ft	No
X	42.1	-2.1 ft	No
110 P400 X AWD	42.1	-2.1 ft	No
110 P500 X-Dynamic SE AWD	42.1	-2.1 ft	No
130 P400 X AWD	42.1	-2.1 ft	No
90 P525 V8 AWD	38	+2 ft	Yes
90 V8 AWD	42.1	-2.1 ft	No
V8	42.1	-2.1 ft	No
110 P525 V8 AWD	42.1	-2.1 ft	No
130 P500 V8 AWD	42.1	-2.1 ft	No
OCTA	42.1	-2.1 ft	No
110 P635 OCTA AWD	42.1	-2.1 ft	No
OCTA Edition One	42.1	-2.1 ft	No
110 P635 OCTA Edition One AWD	42.1	-2.1 ft	No
110 OCTA AWD	42.1	-2.1 ft	No
110 OCTA Edition One AWD	42.1	-2.1 ft	No
110 S AWD	42.1	-2.1 ft	No
110 Sedona Red AWD	42.1	-2.1 ft	No
110 V8 AWD	42.1	-2.1 ft	No
110 X AWD	42.1	-2.1 ft	No
110 X-Dynamic SE AWD	42.1	-2.1 ft	No
130 Outbound AWD	42.1	-2.1 ft	No
130 S AWD	42.1	-2.1 ft	No
130 V8 AWD	42.1	-2.1 ft	No
130 X AWD	42.1	-2.1 ft	No
130 X-Dynamic SE AWD	42.1	-2.1 ft	No
90 S AWD	42.1	-2.1 ft	No
90 X-Dynamic SE AWD	42.1	-2.1 ft	No

What this cannot tell you

Curb-to-curb turning circle as listed.

Mirrors and overhang need more room.