Boring question #43: Does the UK have different dialects and accents among its population?

Henry Ian Cusick Lost Desmond Hume, Nick Watt Nightline, Jamie Oliver, Gordon Ramsay, and Dominic Monaghan Lost, Lord of The Rings are all British, or is the English, but to me they all have different inflection or nuances in their speech. Are there different dialects and accents among Englishmen limiting to just the borders of England, excluding Scotland, Wales, Ireland, etc as there are here in the US with Southern, Boston, New York, New Orleans accents etc? Do they sound slightly different to you, or is it just my ears playing tricks on me? Are some of them actually Welch, Scottish, etc? I think I can tell Irish when I hear it, mostly anyhow.