Results for the UK general election on 6 May 2010 Great Britain - Elections contested by Plaid Cymru
| Constituency | Candidate | Electorate | Turnout | Votes | Vote share | Vote change | Position |
| Swansea East | JONES, Dic | 59,823 | 54.6% | 2,181 | 6.7% | -0.2% | 4th |
| Swansea West | ROBERTS, Harri | 61,334 | 58.0% | 1,437 | 4.0% | -2.5% | 4th |
| Merthyr Tydfil and Rhymney | JONES, Glyndwr | 54,715 | 58.6% | 1,621 | 5.1% | -4.9% | 5th |
| Cynon Valley | DAVIES, Dafydd Trystan | 50,650 | 59.0% | 6,064 | 20.3% | +6.8% | 2nd |
| Cardiff Central | WILLIAMS, Chris | 61,165 | 59.1% | 1,246 | 3.4% | -0.1% | 4th |
| Cardiff South and Penarth | ASLAM, Farida | 73,707 | 60.2% | 1,851 | 4.2% | -1.1% | 4th |
| Rhondda | DAVIES, Geraint | 51,554 | 60.3% | 5,630 | 18.1% | +2.2% | 2nd |
| Aberavon | NICHOLLS-JONES, Paul | 50,838 | 60.9% | 2,198 | 7.1% | -4.7% | 4th |
| Torfaen | AB ELIS, Rhys ab | 61,183 | 61.5% | 2,005 | 5.3% | -0.9% | 4th |
| Blaenau Gwent | DAVIES, Rhodri | 52,442 | 61.8% | 1,333 | 4.1% | +1.7% | 5th |
| Caerphilly | WHITTLE, Lindsay | 62,122 | 62.3% | 6,460 | 16.7% | -1.4% | 3rd |
| Ogmore | CLARK, Danny | 55,527 | 62.4% | 3,326 | 9.6% | -0.6% | 4th |
| Pontypridd | BELLIN, Ioan | 58,205 | 63.0% | 2,673 | 7.3% | -3.7% | 4th |
| Islwyn | LEWIS, Steffan | 54,866 | 63.2% | 4,518 | 13.0% | +0.6% | 3rd |
| Arfon | WILLIAMS, Hywel | 41,198 | 63.3% | 9,383 | 36.0% | +3.9% | 1st |
| Newport East | CROSS, Fiona | 54,437 | 63.3% | 724 | 2.1% | -1.7% | 5th |
| Vale of Clwyd | WYN-JONES, Caryl | 55,781 | 63.7% | 2,068 | 5.8% | -1.4% | 4th |
| Dwyfor Meirionnydd | LLWYD, Elfyn | 45,354 | 63.7% | 12,814 | 44.3% | -6.4% | 1st |
| Ceredigion | JAMES, Penri | 59,882 | 63.9% | 10,815 | 28.3% | -7.6% | 2nd |
| Newport West | REES, Jeff | 62,111 | 64.0% | 1,122 | 2.8% | -0.8% | 6th |
| Clwyd South | RYDER, Janet | 53,748 | 64.5% | 3,009 | 8.7% | -0.8% | 4th |
| Wrexham | JONES, Arfon | 50,872 | 64.8% | 2,029 | 6.2% | +0.4% | 4th |
| Neath | LLEWELYN, Alun | 57,295 | 64.8% | 7,397 | 19.9% | +2.8% | 2nd |
| Cardiff West | ISLAM, Mohammed Sarul | 62,787 | 65.2% | 2,868 | 7.0% | -5.9% | 4th |
| Bridgend | THOMAS, Nick | 58,700 | 65.3% | 2,269 | 5.9% | -1.0% | 4th |
| Alyn and Deeside | JONES, Maurice | 60,931 | 65.5% | 1,549 | 3.9% | +0.2% | 4th |
| Clwyd West | GRUFFYDD, Llyr Huws | 57,913 | 65.8% | 5,864 | 15.4% | +4.5% | 3rd |
| Aberconwy | EDWARDS, Phil | 44,593 | 67.2% | 5,341 | 17.8% | +3.8% | 4th |
| Llanelli | DAVIES, Myfanwy | 55,637 | 67.3% | 11,215 | 29.9% | +3.5% | 2nd |
| Gower | PRICE, Darren | 61,696 | 67.5% | 2,760 | 6.6% | -1.2% | 4th |
| Ynys Môn | REES, Dylan | 50,075 | 68.8% | 9,029 | 26.2% | -4.9% | 2nd |
| Preseli Pembrokeshire | JONES-DAVIES, Henry | 57,400 | 69.0% | 3,654 | 9.2% | -3.3% | 4th |
| Delyn | RYDER, Peter | 53,470 | 69.2% | 1,844 | 5.0% | -2.4% | 4th |
| Vale of Glamorgan | JOHNSON, Ian | 70,211 | 69.3% | 2,667 | 5.5% | +0.3% | 4th |
| Montgomeryshire | FYCHAN, Heledd | 48,730 | 69.4% | 2,802 | 8.3% | +1.3% | 3rd |
| Carmarthen West and South Pembrokeshire | DIXON, John | 58,108 | 69.7% | 4,232 | 10.4% | -5.1% | 4th |
| Monmouth | CLARK, Jonathan | 64,538 | 72.1% | 1,273 | 2.7% | +0.6% | 4th |
| Brecon and Radnorshire | DAVIES, Janet | 53,589 | 72.5% | 989 | 2.5% | -1.1% | 4th |
| Carmarthen East and Dinefwr | EDWARDS, Jonathan | 52,385 | 72.6% | 13,546 | 35.6% | -10.2% | 1st |
| Cardiff North | RHYS, Llywelyn | 65,553 | 72.7% | 1,588 | 3.3% | -0.9% | 4th |
Turnout as calculated by the House of Commons Library, is the total number of votes cast and not spoiled, divided by the size of the electorate.
Under section 13(b) of the Representation of the People Act 1985, a candidate gaining 5% or less of the vote share will forfeit their deposit.
This was the first election on a new set of constituency boundaries in England, Northern Ireland and Wales. The vote share calculations in those countries are based on notional results, which estimate the outcome of the previous election had it been contested on the new boundaries.