James Kennedy is off the hook in his domestic violence case -- no charges will be filed against him ... TMZ has learned.

Kennedy's lawyer, Scott Leemon, tells us the Burbank City Attorney's Office just informed him of their decision.

Leemon adds ... Prosecutors' "diligent investigation confirmed what we have maintained from the beginning -- there were no grounds for any charges to be filed against Mr. Kennedy."

Leemon says Kennedy is happy to put the matter behind him, and is looking forward to continuing to focus on his sobriety, and his DJ career.

As we previously reported ... the "Vanderpump Rules" alum was arrested last month for misdemeanor domestic violence following an argument with an unnamed woman in California.

According to the Burbank Police Department’s arrest log, the woman claimed her boyfriend picked her up and threw her to the ground.

Shortly after the arrest, Ally Lewber -- who was not named as the victim -- released a statement saying she's doing fine but taking the time she needs ... and asked people to respect her privacy.

As for James, he said he was going to take some time away to focus on himself ... adding, "I am committed to making meaningful changes in my life. I am taking time to focus on my sobriety, personal growth, and being present for my loved ones."