• Years of the 20th century in Wales (100 C, 100 P)

/

• 20th-century disestablishments in Wales (11 C)
• 20th-century establishments in Wales (10 C, 2 P)

0–9

• 1900s in Wales (14 C, 11 P)
• 1910s in Wales (15 C, 11 P)
• 1920s in Wales (16 C, 11 P)
• 1930s in Wales (16 C, 12 P)
• 1940s in Wales (16 C, 12 P)
• 1950s in Wales (16 C, 11 P)
• 1960s in Wales (16 C, 10 P)
• 1970s in Wales (16 C, 11 P)
• 1980s in Wales (16 C, 10 P)
• 1990s in Wales (17 C, 14 P)

B

• 20th-century Roman Catholic bishops in Wales (12 P)

C

• 20th century in Cardiff (9 C, 4 P)
• 20th century in Carmarthenshire (42 P)
• 20th century in Ceredigion (25 P)
• 20th-century Church in Wales church buildings (8 P)

D

• Dyfed County Council elections (6 P)

E

• 20th-century elections in Wales (10 C)

G

• 20th century in Glamorgan (7 C, 4 P)

M

• Mid Glamorgan County Council elections (5 P)
• 20th century in Monmouthshire (15 P)

P

• 20th century in Pembrokeshire (4 P)
• 20th-century Welsh people (4 C, 13 P)
• Welsh Poor Laws (1 C, 1 P)

S

• South Glamorgan County Council elections (6 P)
• 20th century in Swansea (13 P)

T

• 20th century in Welsh television (6 C)

W

• Wales in World War II (2 C, 4 P)