This page lists the World Best Year Performance in the year 2005 in the men's decathlon. The main event during this season were the 2005 World Championships in Helsinki, Finland, where the competition started on Tuesday August 9, 2005 and ended on Wednesday August 10, 2005 in the Helsinki Olympic Stadium.
| Rank | Points | Athlete | Venue | Date | Note | |
|---|---|---|---|---|---|---|
| 1 | 8732 | Helsinki, Finland | 2005-08-10 | |||
| 2 | 8534 | Götzis, Austria | 2005-05-29 | |||
| 3 | 8526 | Arles, France | 2005-06-05 | |||
| 4 | 8480 | Götzis, Austria | 2005-05-29 | |||
| 5 | 8429 | Götzis, Austria | 2005-05-29 | |||
| 6 | 8316 | Helsinki, Finland | 2005-08-10 | |||
| 7 | 8290 | Götzis, Austria | 2005-05-29 | |||
| 8 | 8232 | San Juan, Puerto Rico | 2005-05-29 | |||
| 9 | 8196 | Erfurt, Germany | 2005-07-15 | |||
| 10 | 8185 | Götzis, Austria | 2005-05-29 | |||
| 11 | 8149 | Bydgoszcz, Poland | 2005-07-03 | |||
| 12 | 8114 | Götzis, Austria | 2005-05-29 | |||
| 13 | 8107 | Salo, Finland | 2005-05-08 | |||
| 14 | 8105 | Jyväskylä, Finland | 2005-07-03 | |||
| 15 | 8090 | Sochi, Russia | 2005-05-18 | |||
| 16 | 8051 | Izmir, Turkey | 2005-08-19 | |||
| 17 | 8042 | Helsinki, Finland | 2005-08-10 | |||
| 18 | 8025 | Talence, France | 2005-09-18 | |||
| 19 | 8023 | Helsinki, Finland | 2005-08-10 | |||
| 20 | 7997 | San Juan, Puerto Rico | 2005-05-29 | |||
| 21 | 7989 | Erfurt, Germany | 2005-07-15 | |||
| 22 | 7976 | Carson, United States | 2005-06-24 | |||
| 23 | 7975 | Götzis, Austria | 2005-05-29 | |||
| 24 | 7950 | Talence, France | 2005-09-18 | |||
| 25 | 7920 | Götzis, Austria | 2005-05-29 |