The 2009 IIHF World U20 Championship Division I took place between December 14 and December 21, 2008 in Herisau, Switzerland and Aalborg, Denmark. Teams were divided into two groups, with Group A playing in Switzerland, and Group B playing in Denmark. The winner of each group is promoted to the Top Division for the 2010 IIHF World U20 Championship, while the last place teams in each group are relegated to Division II for the 2010 IIHF World U20 Championship.
| Team | GP | W | OTW | OTL | L | GF | GA | DIF | PTS |
|---|---|---|---|---|---|---|---|---|---|
| Switzerland | 5 | 5 | 0 | 0 | 0 | 31 | 7 | 24 | 15 |
| Belarus | 5 | 4 | 0 | 0 | 1 | 39 | 7 | 32 | 12 |
| France | 5 | 3 | 0 | 0 | 2 | 33 | 17 | 16 | 9 |
| Slovenia | 5 | 2 | 0 | 0 | 3 | 31 | 17 | 14 | 6 |
| Poland | 5 | 1 | 0 | 0 | 4 | 7 | 23 | -16 | 3 |
| Estonia | 5 | 0 | 0 | 0 | 5 | 6 | 76 | -70 | 0 |
| Team | GP | W | OTW | OTL | L | GF | GA | DIF | PTS |
|---|---|---|---|---|---|---|---|---|---|
| Austria | 5 | 4 | 0 | 1 | 0 | 28 | 9 | 19 | 13 |
| Denmark | 5 | 4 | 0 | 0 | 1 | 16 | 13 | 3 | 12 |
| Norway | 5 | 2 | 1 | 0 | 2 | 14 | 17 | -3 | 8 |
| Italy | 5 | 2 | 1 | 0 | 2 | 14 | 10 | 4 | 8 |
| Ukraine | 5 | 1 | 0 | 0 | 4 | 10 | 16 | -6 | 3 |
| Hungary | 5 | 0 | 0 | 1 | 4 | 11 | 28 | -17 | 1 |
Switzerland and Austria were promoted to the top division for the 2010 Championships, while Estonia and Hungary were relegated to Division II.
| Preceded by 2008 World Junior Ice Hockey Championships - Division I |
World Junior Ice Hockey Championships - Division I 2009 |
Succeeded by 2010 World Junior Ice Hockey Championships - Division I |