The hotel heiress – who recently split from long-term boyfriend Cy Waits – and the 'Hangover' director enjoyed a night out at Hollywood's Beacher's Madhouse this week, where they sat at a secluded table along with Paris' sister Nicky.
According to onlookers, the pair weren't discreet and spent most of the night kissing and gazing into each other's eyes.
Earlier in the night, Paris and Todd went to the nearby Chateau Marmont, where they enjoyed wine on the patio with friends.
Paris, 30, split from nightclub entrepreneur Cy last month after 18 months of dating, but insisted they would still be friends.
She said: "Cy is a good guy. We've been friends for years and it will not change. I just need some time alone to think about myself. We talk all the time. I have nothing but nice things to say about it."
While Paris is coping with the split, her mother Kathy said she was "heartbroken" by the news.
Speaking about Cy, she: "He really is an angel. I do adore him. My heart is broken. That's why I don't like getting close to the boyfriends because they become like a part of the family."