The former Bond girl, 35, has been shooting scenes in St Anne's, close to the pier and on the beach and was almost unrecognisable in a bleach blonde wig and retro-inspired costume.
The series is understood to be a yet-unnamed adaptation of Nick Hornby's best-selling novel Funny Girl.
Earlier this week the cast which also includes Rupert Everett, David Threlfall and Tom Bateman had been filming in Liverpool.
Gemma's sighting in the Fylde comes as other shots emerged of from the currently-untitled comedy mini-series. Gemma will star as Barbara Parker, a charismatic young woman who holds the title of Miss Blackpool.
Tom Bateman was also seen on-set by onlookers.
Fans will have to wait until next year to see the resort once again take centre stage in another major TV series. It follows the filming of Star Wars Andor in Cleveleys, the featuring of the Tower Ballroom in the new Amazon Prime musical movie Cinderella and the upcoming Netflix series Stay Close, which saw a large scale production move into the centre of Blackpool earlier in the summer.
James Nesbitt is the star behind the British crime drama series. spectacle where Barbara finds her comic voice in a male dominated world.
Speaking of her role in the new Sky show Gemma said: 'It's a heart-warming story of an ambitious woman with a dream of making people laugh – it's going to be something special.
'It's an honour to be working with such an incredible team and be reunited with my first ever director, Oliver Parker.'
The Sky Original comedy drama will be available on Sky Max and streaming service NOW in 2022.