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 |
| Carmarthen East and Dinefwr | EDWARDS, Jonathan | 52,385 | 72.6% | 13,546 | 35.6% | -10.2% | 1st |
| Dwyfor Meirionnydd | LLWYD, Elfyn | 45,354 | 63.7% | 12,814 | 44.3% | -6.4% | 1st |
| Llanelli | DAVIES, Myfanwy | 55,637 | 67.3% | 11,215 | 29.9% | +3.5% | 2nd |
| Ceredigion | JAMES, Penri | 59,882 | 63.9% | 10,815 | 28.3% | -7.6% | 2nd |
| Arfon | WILLIAMS, Hywel | 41,198 | 63.3% | 9,383 | 36.0% | +3.9% | 1st |
| Ynys Môn | REES, Dylan | 50,075 | 68.8% | 9,029 | 26.2% | -4.9% | 2nd |
| Neath | LLEWELYN, Alun | 57,295 | 64.8% | 7,397 | 19.9% | +2.8% | 2nd |
| Caerphilly | WHITTLE, Lindsay | 62,122 | 62.3% | 6,460 | 16.7% | -1.4% | 3rd |
| Cynon Valley | DAVIES, Dafydd Trystan | 50,650 | 59.0% | 6,064 | 20.3% | +6.8% | 2nd |
| Clwyd West | GRUFFYDD, Llyr Huws | 57,913 | 65.8% | 5,864 | 15.4% | +4.5% | 3rd |
| Rhondda | DAVIES, Geraint | 51,554 | 60.3% | 5,630 | 18.1% | +2.2% | 2nd |
| Aberconwy | EDWARDS, Phil | 44,593 | 67.2% | 5,341 | 17.8% | +3.8% | 4th |
| Islwyn | LEWIS, Steffan | 54,866 | 63.2% | 4,518 | 13.0% | +0.6% | 3rd |
| Carmarthen West and South Pembrokeshire | DIXON, John | 58,108 | 69.7% | 4,232 | 10.4% | -5.1% | 4th |
| Preseli Pembrokeshire | JONES-DAVIES, Henry | 57,400 | 69.0% | 3,654 | 9.2% | -3.3% | 4th |
| Ogmore | CLARK, Danny | 55,527 | 62.4% | 3,326 | 9.6% | -0.6% | 4th |
| Clwyd South | RYDER, Janet | 53,748 | 64.5% | 3,009 | 8.7% | -0.8% | 4th |
| Cardiff West | ISLAM, Mohammed Sarul | 62,787 | 65.2% | 2,868 | 7.0% | -5.9% | 4th |
| Montgomeryshire | FYCHAN, Heledd | 48,730 | 69.4% | 2,802 | 8.3% | +1.3% | 3rd |
| Gower | PRICE, Darren | 61,696 | 67.5% | 2,760 | 6.6% | -1.2% | 4th |
| Pontypridd | BELLIN, Ioan | 58,205 | 63.0% | 2,673 | 7.3% | -3.7% | 4th |
| Vale of Glamorgan | JOHNSON, Ian | 70,211 | 69.3% | 2,667 | 5.5% | +0.3% | 4th |
| Bridgend | THOMAS, Nick | 58,700 | 65.3% | 2,269 | 5.9% | -1.0% | 4th |
| Aberavon | NICHOLLS-JONES, Paul | 50,838 | 60.9% | 2,198 | 7.1% | -4.7% | 4th |
| Swansea East | JONES, Dic | 59,823 | 54.6% | 2,181 | 6.7% | -0.2% | 4th |
| Vale of Clwyd | WYN-JONES, Caryl | 55,781 | 63.7% | 2,068 | 5.8% | -1.4% | 4th |
| Wrexham | JONES, Arfon | 50,872 | 64.8% | 2,029 | 6.2% | +0.4% | 4th |
| Torfaen | AB ELIS, Rhys ab | 61,183 | 61.5% | 2,005 | 5.3% | -0.9% | 4th |
| Cardiff South and Penarth | ASLAM, Farida | 73,707 | 60.2% | 1,851 | 4.2% | -1.1% | 4th |
| Delyn | RYDER, Peter | 53,470 | 69.2% | 1,844 | 5.0% | -2.4% | 4th |
| Merthyr Tydfil and Rhymney | JONES, Glyndwr | 54,715 | 58.6% | 1,621 | 5.1% | -4.9% | 5th |
| Cardiff North | RHYS, Llywelyn | 65,553 | 72.7% | 1,588 | 3.3% | -0.9% | 4th |
| Alyn and Deeside | JONES, Maurice | 60,931 | 65.5% | 1,549 | 3.9% | +0.2% | 4th |
| Swansea West | ROBERTS, Harri | 61,334 | 58.0% | 1,437 | 4.0% | -2.5% | 4th |
| Blaenau Gwent | DAVIES, Rhodri | 52,442 | 61.8% | 1,333 | 4.1% | +1.7% | 5th |
| Monmouth | CLARK, Jonathan | 64,538 | 72.1% | 1,273 | 2.7% | +0.6% | 4th |
| Cardiff Central | WILLIAMS, Chris | 61,165 | 59.1% | 1,246 | 3.4% | -0.1% | 4th |
| Newport West | REES, Jeff | 62,111 | 64.0% | 1,122 | 2.8% | -0.8% | 6th |
| Brecon and Radnorshire | DAVIES, Janet | 53,589 | 72.5% | 989 | 2.5% | -1.1% | 4th |
| Newport East | CROSS, Fiona | 54,437 | 63.3% | 724 | 2.1% | -1.7% | 5th |
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.