Manor has confirmed Rio Haryanto will drive alongside Pascal Wehrlein this year, meaning the last available place on the 2016 grid has been taken.
Haryanto finished fourth in GP2 last year with three victories after four full seasons in Formula One's feeder series. He brings financial backing from the Indonesian state government and will become the first Indonesian to race in Formula One.
"Manor Racing is a team with an exciting vision and ambitious plans. They have produced a great package and I can't wait to get in the car. Melbourne will be a huge moment for me, my country, supporters and fans and I want to thank everyone who's been with me since I started in single seaters; 2016 is my chance to reward that faith and represent Asia in F1."
Manor's owner Stephen Fitzpatrick added: "We are delighted to announce Rio as our second race driver for 2016. Rio's been racing since he first got into a kart at six years old. He's tenacious on and off the track and made a big impression on last year's GP2 battle. Rio's huge following in Indonesia is great for the team and for F1. They are keen to see him on the grid and we're confident that we'll see him enjoying some exciting battles in the year ahead."
Haryanto is due to test for Manor next week at the first pre-season test and will race alongside Mercedes protégé Wehrlein this year.