The 27-year-old 'Applause' hitmaker is the latest celebrity being lined up for a cameo in the film, alongwith Adele, Taylor Swift, Elton John and David Beckham, reported Contactmusic.
"Gaga only had to commit one day to film her scenes early next year. She's such an Anglophile she didn't take much persuading," a source said.
"The Secret Service", which is based on a graphic novel by Mark Millar and Dave Gibbons, will follow Colin Firth as a suave secret agent who is tasked with teaching the tricks of the trade to his young protege.
Gaga has been stretching her talents across the film world after landing her debut acting role in Robert Rodriguez's dark action movie "Machete Kills", which is due for release later this year.
The 'Poker Face' star plays gun-toting vixen La Chameleon in the film, which sees her act alongside Jessica Alba, Charlie Sheen and Sofia Vergara.
Gaga also filmed a cameo for next year's "Sin City: A Dame to Kill For".