The communications giant is offering up to 100 paid internships and 60 graduate roles with many based at its head office in Bath Road, Slough.
The intern programme offers 100 undergraduates a paid placement in areas including marketing, sales, IT and business and retail.
The graduate scheme is a two-year programme with roles available in marketing, IT, retail and leadership.
Ann Pickering, HR director at O2, said: "We believe there is an untapped wealth of skill and knowledge sitting firmly within the youth community, but not enough is being done to harness it.
"All businesses, big and small, have a role to play in supporting young people on their journey to work. Whether it's offering quality work experiences, mentoring or training - every opportunity counts."
To apply visit www.telefonicaando2careers.com