A number of teams are getting some on-track running in before the first race of the year, as they practice new safety protocols implemented as a result of the coronavirus pandemic.
Ocon, who was driving the 2018 Renault R.S.18 in a black livery, clocked 143 laps of the Spielberg circuit, following teammate Daniel Ricciardo's 115-lap test on Tuesday.
Testing regulations require that for on-track running that's outside of official sessions, teams run a car that's at least two years old.
Speaking last month about his return, Ocon said: “I'm waiting for so long now, I want to get back. But I'm in a good position, I have a contract signed, I'm ready to go when everything restarts. So I'm just waiting patiently to get going.”
Renault is looking to recapture the status of the midfield's leading team, having lost fourth place in the constructors' championship to McLaren last year.
Bahrain International Circuit - Winter testing