The £10.5m package will see 40 new jobs at the broadcaster, including 25 additional journalist posts.
It will support the equivalent of 100 jobs across the independent TV sector.
Director Rhodri Talfan Davies said it would ensure BBC Wales was "a bold and ambitious broadcaster for the whole nation, young and old".
According to BBC Wales, £8.5m of the investment is new funding and follows pledges to spend more on programmes in February.
It follows announcements last week on plans for a new monthly debate programme and a new weekly current affairs programme for Wales.
The broadcaster has also said it will expand FM coverage for Radio Wales in north and mid Wales, and is launching a new morning service for Radio Cymru.
"Audiences in Wales already rate the BBC more highly than any other UK nation, but this is an unprecedented opportunity to deepen our connection with viewers and listeners in every part of the nation," added the BBC Wales director.
"We're putting entertainment right at the heart of our plans - and we have an exciting range of new comedy and drama projects in the pipeline with some of our nation's biggest and brightest talents.
BBC Wales will deliver its biggest single investment for two decades for television, radio and mobile services, it has been announced.