Children's programmes will no longer be shown on BBC One and Two following the digital switchover, the BBC Trust has confirmed.
Award-winning shows such as Horrible Histories and Blue Peter will move permanently to CBBC and CBeebies.
No date has been set for the change, but the final analogue transmitters will be switched off in Northern Ireland between 10-24 October.
The confirmation came in a report approving the BBC's cost-cutting plans.
Spending on children's programmes will not be affected, and the move is unlikely to be detrimental to viewing figures.
In recent months, the number of young people watching children's programmes on the BBC's main terrestrial channels has occasionally dropped as low as 1,000.
Figures on digital have steadily increased since its introduction of CBBC and CBeebies in 2002.
Blue Peter, for example, is now seen by an average audience of 123,000 6-12 year olds when it is shown on CBBC.
BBC One repeats of the show are watched by an average of 30,000 children in the same age range.
A Trust spokesperson said: "Children's programmes are absolutely fundamental to the BBC and that is why we have protected investment in them in the light of cuts elsewhere.
"Only a very small percentage of children still solely watch these programmes on BBC One and BBC Two alone, so moving them to digital channels is merely following current viewing patterns and reflects the fact that CBeebies and CBBC will be universally available on digital TV from the end of this year."
Local radio cuts 'halved'
The BBC Trust document was its final report into cost-saving plans known internally as "Delivering Quality First".
It confirmed that cuts to local radio and TV services would be halved - with savings now in the region of £8m, compared to the original proposal of £15m.
As a result, reductions in local news teams will be lower, and coverage of local sport will be "more protected", the Trust said.
A plan for local radio stations to share programmes in the afternoon will now be limited to a "very small number" of stations.
However, on weekday evenings between 19:00 and 22:00, all of the BBC's regional stations in England will join together for a new all-England programme, although stations will have the flexibility to opt for local sports coverage.
Across the BBC, some of the main points noted by the BBC Trust were:
- BBC One and Two will "largely be protected from making significant cuts".
- Repeats on BBC One will increase, but remain under 10% of all output (the current rate is 8.4%).
- Expenditure on sports rights will be cut by 15%. This has largely been achieved already by sharing rights to Formula 1 coverage.
- Regional music programmes on Radio 1 will be replaced with a single programme "that offers a UK-wide platform for undiscovered, unsigned" bands.
- Radio 3 will have "25 per cent fewer live and specially recorded lunchtime concerts".
- Plans to drop 5 live's weekly one hour current affairs programme have been dropped.
- Asian Network will increase its music content, and cease to broadcast between midnight and 06:00.
The BBC Trust, which is the governing body of the BBC, drew up its report in consultation with listeners, viewers and other broadcasters.
BBC management responded to the report, saying: "We welcome the BBC Trust's full approval of our Delivering Quality First proposals.
"The coming years will involve a significant effort from people at every level of the BBC to deliver the savings while we continue to provide the quality programmes and services that audiences expect from us."