Paris Hilton Dresses as Britney Spears in '...Baby One More Time' for Halloween

Paris Hilton's giving fans a sign ... posting pics of herself on Instagram dressed as her close pal Britney Spears -- holding a diary that reads "Bad Bitch" across the cover.

The reality TV star shared several photos of her "...Baby One More Time" inspired outfit ... gray sweater and matching mini-skirt, and a white button-down shirt tied at the bottom to show off her tanned, toned stomach.

Waiting for your permission to load the Instagram Media.

Check out the photos ... Paris is putting some cleavage on display -- posing with several sultry looks while leaning back on bright pink lockers. Brit's music vid is a bit more gray than Paris' interpretation, but ya know Hilton had to include her signature color for her shoot.

In other pics, Paris uses a traditional-looking high school desk as a prop ... throwing a stocking-covered leg over the back of it and holding a pen near her mouth.

Hilton wrote, "It’s Britney bitch 😉💕 Love you icon @BritneySpears 🥰💖" in the caption.

Worth noting ... Paris and Brit occasionally ran in the same circles back in the early 2000s -- and, they're still pretty good friends, with Britney totally loving Paris' son Phoenix.

In Britney's memoir "The Woman in Me," Spears wrote Hilton was "one of the people who was kindest to me when I really needed kindness."

Looks like there's a lot of love between these two -- no "Toxic" relationship whatsoever!