Ronnie Radke is taking his first steps toward figuring out who is allegedly impersonating him online … filing a lawsuit in an effort to subpoena Snapchat.

The singer and rapper filed a suit against multiple John Does earlier this week … alleging that, since at least April of last year, an individual he calls John Doe 1 has credibly impersonated him on Snapchat for “purposes of harming, intimidating, threatening and/or defrauding” others.

He’s also suing John Doe 2 — who may or may not be the same person as John Doe 1 — for allegedly impersonating him on Instagram with the same aim to defraud others.

Ronnie notes he doesn’t know the identities of these alleged impersonators … which is why he’s suing them under these fictitious names until he can figure out who they are.

We reached out to Ronnie … and, he tells us this is the first step in his plan to subpoena Snapchat to get the metadata and IP address he believes necessary to prove he never messaged anyone, including Brittany Furlan.

Ronnie says he doesn’t want money … just evidence to clear his name and prove he wasn’t hitting up Tommy Lee‘s wife last year.

As you know … Ronnie filed a temporary restraining order against Furlan earlier this week — claiming she’s harassing him online and even showed up at his house.

Furlan admitted to being catfished by someone pretending to be Ronnie last year … but recently changed her tune and claimed she was talking to the real Ronnie — before she allegedly contacted some of Ronnie’s underage fans online and encouraged them to come forward with alleged inappropriate experiences with the singer.