The mixed 4 × 100 metre medley relay event at the 2010 Youth Olympic Games took place on August 20, at the Singapore Sports School.
Medalists edit
| Gold |  China |
3:52.52 |
| Silver |  Russia |
3:55.29 |
| Bronze |  Australia |
3:55.63 |
Heats edit
Heat 1 edit
| Rank | Lane | Nationality | Time | Notes |
|---|---|---|---|---|
| 1 | 5 | China
|
3:56.78 | Q |
| 2 | 2 |  Spain
|
4:07.05 | |
| 3 | 4 |  Hong Kong
|
4:14.66 | |
| 4 | 6 |  Serbia
|
4:21.02 | |
| 3 |  Italy
|
DNS |
Heat 2 edit
| Rank | Lane | Nationality | Time | Notes |
|---|---|---|---|---|
| 1 | 6 | Russia
|
4:00.67 | Q |
| 2 | 4 |  France
|
4:00.82 | Q |
| 3 | 5 |  Canada
|
4:02.69 | Q |
| 4 | 7 |  United States
|
4:04.29 | Q |
| 5 | 2 |  South Africa
|
4:06.14 | |
| 6 | 3 |  Iceland
|
4:18.81 |
Heat 3 edit
| Rank | Lane | Nationality | Time | Notes |
|---|---|---|---|---|
| 1 | 4 | Australia
|
3:59.14 | Q |
| 2 | 3 |  Germany
|
4:02.56 | Q |
| 3 | 6 |  Japan
|
4:06.13 | Q |
| 4 | 5 |  Brazil
|
4:08.25 | |
| 5 | 2 |  Singapore
|
4:08.94 | |
| 6 | 7 |  Trinidad and Tobago
|
4:20.21 |
Final edit
| Rank | Lane | Nationality | Time | Notes |
|---|---|---|---|---|
|
4 | China
|
3:52.52 | |
|
3 | Russia
|
3:55.29 | |
|
5 | Australia
|
3:55.63 | |
| 4 | 6 | France
|
3:56.64 | |
| 5 | 7 | Canada
|
4:02.22 | |
| 6 | 1 | United States
|
4:02.90 | |
| 7 | 8 | Japan
|
4:06.18 | |
| 2 | Germany
|
DSQ |