http://en.wikipedia.org/wiki/List_of_largest_United_Kingdom_settlements_by_population

or for the link-averse:

1 London 7,172,091
2 Birmingham 970,892
3 Glasgow 629,501
4 Liverpool 469,017
5 Manchester 464,200
6 Leeds 443,247
7 Sheffield 439,866
8 Edinburgh 430,082
9 Bristol 420,556
10 Cardiff 341,054
11 Leicester 330,574
12 Coventry 303,475
13 Kingston upon Hull 301,416
14 Bradford 293,717
15 Belfast 276,459
16 Newcastle upon Tyne
17 Stoke-on-Trent 259,252
18 Wolverhampton 251,462
19 Nottingham 249,584
20 Plymouth 243,795

Me: Glasgow