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