| Election Name: | 2005 Lancashire County Council election |
| Country: | England |
| Type: | Parliamentary |
| Ongoing: | no |
| Party Colour: | yes |
| Previous Election: | 2001 Lancashire County Council election |
| Previous Year: | 2001 |
| Next Election: | 2009 Lancashire County Council election |
| Next Year: | 2009 |
| Seats For Election: | All 84 seats to Lancashire County Council |
| Majority Seats: | 43 |
| Election Date: | 5 May 2005 |
| Party1: | Labour Party (UK) |
| Seats1: | 44 |
| Popular Vote1: | 197,061 |
| Percentage1: | 37.62% |
| Party2: | Conservative Party (UK) |
| Seats2: | 31 |
| Popular Vote2: | 195,517 |
| Percentage2: | 37.33% |
| Party3: | Liberal Democrats (UK) |
| Seats3: | 6 |
| Popular Vote3: | 99,710 |
| Percentage3: | 19.04% |
| Party4: | Green Party of England and Wales |
| Seats4: | 1 |
| Popular Vote4: | 8,350 |
| Percentage4: | 1.60% |
| Party5: | Independent (politician) |
| Seats5: | 1 |
| Popular Vote5: | 7,417 |
| Percentage5: | 1.42% |
| Party6: | Idle Toad |
| Seats6: | 1 |
| Popular Vote6: | 1,680 |
| Percentage6: | 0.32 |
| Council control | |
| Posttitle: | Council control after election |
| After Election: | Labour Party |
Elections to Lancashire County Council were held on 5 May 2005, on the same day as the 2005 general election.
Each single-member ward in Lancashire was modified by boundary changes. No elections were held in Blackpool or Blackburn as they are unitary authorities outside of the county boundaries.
The overall turnout was 60.48% with a total of 523,763 valid votes cast. A total of 4,385 ballots were rejected.
Following the election, the composition of the council was:
| 44 | 31 | 6 | 1 | 1 | 1 | |
| Labour | Conservative | Lib Dem | G | I | IT |