They reunited after the Monte Carlo actress revealed she had a kidney transplant over the summer due to her lupus.
She just split with her boyfriend of 10 months, The Weeknd.
She was spotted arriving at his rented mansion hours after their meal together.
On Monday, Justin was seen leaving her LA home in the morning; he was driving his white Mercedes Benz G-class SUV.
And on Wednesday, Selena Gomez stepped out again with Justin Bieber for a biking session and a coffee run together in Los Angeles.
At one point, the 25-year-old songstress leaned her head on Justin's shoulder after leaving a local cafe.