The women's javelin throw event at the 2010 World Junior Championships in Athletics was held in Moncton, New Brunswick, Canada, at Moncton Stadium on 20 and 21 July.
| Gold | Sanni Utriainen | |
| Silver | Līna Mūze | |
| Bronze | Tazmin Brits |
21 July
| Rank | Name | Nationality | Attempts | Result | Notes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | ||||||||
| align=left | align=left | | 54.31 | 49.92 | x | x | 55.36 | 56.69 | 56.69 | ||||
| align=left | align=left | 49.44 | x | 45.82 | 56.64 | x | 54.57 | 56.64 | |||||
| align=left | align=left | 50.25 | x | 48.41 | 54.55 | 53.79 | x | 54.55 | |||||
| 4 | align=left | align=left |  | 46.95 | 54.44 | 51.84 | 50.58 | x | 51.95 | 54.44 | |||
| 5 | align=left | align=left |  | 50.61 | 52.50 | 53.29 | 50.22 | x | 49.81 | 53.29 | |||
| 6 | align=left | align=left |  | 51.97 | x | 49.87 | 50.26 | 52.87 | 48.75 | 52.87 | |||
| 7 | align=left | align=left |  | 50.61 | 50.13 | x | 50.70 | x | 48.68 | 50.70 | |||
| 8 | align=left | align=left |  | 50.08 | 49.87 | 48.46 | x | x | 47.70 | 50.08 | |||
| 9 | align=left | align=left | 44.81 | 49.03 | x | 49.03 | |||||||
| 10 | align=left | align=left | 48.89 | x | x | 48.89 | |||||||
| 11 | align=left | align=left |  | 45.83 | x | x | 45.83 | ||||||
| 12 | align=left | align=left | 42.44 | 42.44 | 42.42 | 42.44 | |||||||
20 July
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 47.88 | 45.33 | 55.27 | 55.27 | Q | ||
| 2 | align=left | align=left | 54.87 | - | - | 54.87 | Q | |||
| 3 | align=left | align=left | | 47.31 | 52.99 | 51.69 | 52.99 | q | ||
| 4 | align=left | align=left | 45.74 | 46.77 | 48.92 | 48.92 | q | |||
| 5 | align=left | align=left | 48.68 | 48.10 | 47.79 | 48.68 | q | |||
| 6 | align=left | align=left |  | 42.93 | 47.68 | 48.26 | 48.26 | |||
| 7 | align=left | align=left | | 45.55 | 48.00 | 45.31 | 48.00 | |||
| 8 | align=left | align=left | 41.82 | 46.70 | 44.47 | 46.70 | ||||
| 9 | align=left | align=left |  | 46.68 | 45.86 | 45.30 | 46.68 | |||
| 10 | align=left | align=left | 46.29 | 45.49 | 43.25 | 46.29 | ||||
| 11 | align=left | align=left | | 40.28 | 43.48 | 38.08 | 43.48 | |||
| 12 | align=left | align=left |  | 39.31 | 43.26 | 42.96 | 43.26 | |||
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | 49.16 | 51.99 | 50.42 | 51.99 | q | ||
| 2 | align=left | align=left | 50.86 | 48.44 | 49.11 | 50.86 | q | |||
| 3 | align=left | align=left | | 50.13 | 49.62 | x | 50.13 | q | ||
| 4 | align=left | align=left | | 49.87 | 49.94 | x | 49.94 | q | ||
| 5 | align=left | align=left | | 46.80 | 47.03 | 48.93 | 48.93 | q | ||
| 6 | align=left | align=left | 48.82 | 48.01 | 43.18 | 48.82 | q | |||
| 7 | align=left | align=left | | 48.46 | x | 42.59 | 48.46 | q | ||
| 8 | align=left | align=left |  | 43.85 | 44.17 | 48.22 | 48.22 | |||
| 9 | align=left | align=left |  | 47.86 | 48.10 | 46.67 | 48.10 | |||
| 10 | align=left | align=left |  | 47.96 | x | 47.25 | 47.96 | |||
| 11 | align=left | align=left |  | 45.99 | 45.29 | x | 45.99 | |||
According to an unofficial count, 23 athletes from 19 countries participated in the event.