The men's javelin throw event at the 2010 World Junior Championships in Athletics was held in Moncton, New Brunswick, Canada, at Moncton Stadium on 22 and 23 July.
| Gold | Till Wöschler | |
| Silver | Genki Dean | |
| Bronze | Dmitri Tarabin |
23 July
| Rank | Name | Nationality | Attempts | Result | Notes | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | ||||||||
| align=left | align=left | 82.52 | - | 76.05 | 74.99 | - | 76.08 | 82.52 | |||||
| align=left | align=left | | 68.68 | 73.16 | 71.80 | 76.44 | x | 72.63 | 76.44 | ||||
| align=left | align=left | | 68.23 | 76.42 | x | 73.07 | x | 70.75 | 76.42 | ||||
| 4 | align=left | align=left | 70.63 | 72.56 | 70.19 | 75.66 | x | 68.26 | 75.66 | ||||
| 5 | align=left | align=left |  | 66.61 | 71.23 | 73.14 | 69.05 | 74.64 | 67.45 | 74.64 | |||
| 6 | align=left | align=left | x | 74.13 | x | x | x | 68.38 | 74.13 | ||||
| 7 | align=left | align=left | 73.38 | x | 70.99 | 66.17 | 72.92 | 64.40 | 73.38 | ||||
| 8 | align=left | align=left | x | 71.45 | 71.58 | 65.90 | 69.86 | 68.92 | 71.58 | ||||
| 9 | align=left | align=left | 69.93 | x | 69.25 | 69.93 | |||||||
| 10 | align=left | align=left |  | 68.35 | 69.77 | 69.27 | 69.77 | ||||||
| 11 | align=left | align=left | 63.13 | 68.12 | 66.83 | 68.12 | |||||||
| 12 | align=left | align=left | | 59.96 | 63.80 | 58.75 | 63.80 | ||||||
22 July
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | x | 77.97 | - | 77.97 | Q | |||
| 2 | align=left | align=left | 72.78 | - | - | 72.78 | Q | |||
| 3 | align=left | align=left | | x | 69.44 | 72.20 | 72.20 | Q | ||
| 4 | align=left | align=left | | 64.44 | 63.24 | 70.18 | 70.18 | q | ||
| 5 | align=left | align=left | 69.74 | x | x | 69.74 | q | |||
| 6 | align=left | align=left | x | 65.22 | 69.29 | 69.29 | q | |||
| 7 | align=left | align=left |  | 66.88 | x | 60.10 | 66.88 | |||
| 8 | align=left | align=left | 64.32 | x | x | 64.32 | ||||
| 9 | align=left | align=left |  | 59.34 | 63.75 | x | 63.75 | |||
| 10 | align=left | align=left | 61.81 | x | x | 61.81 | ||||
| 11 | align=left | align=left |  | x | 61.63 | 61.72 | 61.72 | |||
| 12 | align=left | align=left |  | 57.36 | 61.66 | x | 61.66 | |||
| 13 | align=left | align=left | | 55.97 | 57.78 | 60.47 | 60.47 | |||
| 14 | align=left | align=left |  | 60.27 | 58.99 | 59.51 | 60.27 | |||
| 15 | align=left | align=left |  | 59.24 | x | x | 59.24 | |||
| 16 | align=left | align=left |  | 58.24 | x | 58.46 | 58.46 | |||
| align=left | align=left | x | x | x | NM | |||||
| Rank | Name | Nationality | Attempts | Result | Notes | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | ||||||||
| 1 | align=left | align=left | | x | 69.01 | 71.06 | 71.06 | q | ||
| 2 | align=left | align=left | 65.56 | 69.95 | 71.05 | 71.05 | q | |||
| 3 | align=left | align=left | | 70.12 | 68.67 | - | 70.12 | q | ||
| 4 | align=left | align=left | x | 66.69 | 69.44 | 69.44 | q | |||
| 5 | align=left | align=left | | 69.36 | 67.86 | 67.40 | 69.36 | q | ||
| 6 | align=left | align=left | x | 64.80 | 67.89 | 67.89 | q | |||
| 7 | align=left | align=left | 66.26 | 62.61 | 65.93 | 66.26 | ||||
| 8 | align=left | align=left | | 64.37 | 62.44 | 66.15 | 66.15 | |||
| 9 | align=left | align=left | x | 65.21 | 66.05 | 66.05 | ||||
| 10 | align=left | align=left |  | 65.34 | x | 60.02 | 65.34 | |||
| 11 | align=left | align=left |  | 63.79 | x | 58.99 | 63.79 | |||
| 12 | align=left | align=left |  | 60.06 | 61.90 | x | 61.90 | |||
| 13 | align=left | align=left | | 59.15 | x | x | 59.15 | |||
| 14 | align=left | align=left |  | x | x | 57.81 | 57.81 | |||
| 15 | align=left | align=left | x | x | 56.10 | 56.10 | ||||
| align=left | align=left | x | x | x | NM | |||||
According to an unofficial count, 33 athletes from 25 countries participated in the event.