| Welsh: Stwnsh|italic=no | |
| Country: | Wales |
| Runtime: | As of 2019 |
| Language: | Welsh |
, pronounced as /cy/) is a strand of Welsh-language children's television programming on S4C, aimed at children between the ages of seven and thirteen.
Welsh: Stwnsh was launched on Monday 26 April 2010, replacing the former Welsh-language children's strand, . Welsh: Stwnsh is broadcast on S4C every weekday, from 5:00pm to 6:00pm, and on Saturdays as from 8:00am to 10:00am.
The programmes shown as part of this service include both brand-new programmes and programmes that were previously shown as part of Welsh: Planed Plant.
The long-running programme was scrapped by S4C to make way for Welsh: Stwnsh service, although the final episode of Welsh: Uned 5, was not broadcast until Sunday 30 May 2010, just over a month after the launch of the Welsh: Stwnsh service.