Bartley joined the London club two days before this season's Football League campaign kicked off and has gone on to feature in 17 league games for them, five starts and 12 substitute appearances, after making his debut as a substitute in a 3-0 win against Shrewsbury on 10th August.
He's also made four appearances in cup competitions but has not featured for them in the FA Cup and his last game came on 29th December in the top of the table clash at Wolves.
He played the entire ninety minutes against Kevin McDonald, who was briefly a Turf Moor team mate, in a game that ended 1-1.
Leyton Orient boss Russell Slade intimated last week that he'd like to keep Bartley at Brisbane Road and they have confirmed that talks continue with Burnley regarding a longer term deal.
If that was so it would see Bartley finish the season there and to the end of his contract with Burnley.
Bartley joined Burnley right at the end of the January transfer window three years ago, becoming Eddie Howe's second signing. He's made a total of 72 league and cup appearances since making his debut at Watford, and has scored three goals, all of them coming in the league during the 2011/12 season.