Harper's Island Ratings Ratings

| Episode_ | US_air_date | Rating | Share_ | Rating_Share_18_49 | Viewers_millions |
|---|---|---|---|---|---|
| 1 | Thursday, April 9, 2009 | 6.5 | 11 | 2.6/8 | 10.21 |
| 2 | Thursday, April 16, 2009 | 5.1 | 9 | 2.2/6 | 7.82 |
| 3 | Thursday, April 23, 2009 | 4.7 | 9 | 1.9/5 | 7.02 |
| 4 | Saturday, May 2, 2009 | 3.1 | 6 | 1.0/3 | 4.61 |
| 5 | Saturday, May 9, 2009 | 3.1 | 6 | 1.1/3 | 4.60 |
| 6 | Saturday, May 23, 2009 | 2.5 | 5 | 1.0/4 | 3.85 |
| 7 | Saturday, May 30, 2009 | 2.4 | 5 | 0.9/3 | 3.62 |
| 8 | Saturday, June 6, 2009 | 2.4 | 5 | 0.9/3 | 3.56 |
| 9 | Saturday, June 13, 2009 | 2.0 | 4 | 0.8/3 | 3.20 |
| 10 | Saturday, June 20, 2009 | TBA | TBA | 0.9/4 | 3.79 |
| 11 | Saturday, June 27, 2009 | 2.4 | 5 | 0.8/3 | 3.53 |
| 12 | Saturday, July 11, 2009 | 2.4 | 5 | 0.8/3 | 3.63 |