The Get Rich Or Die Tryin’ singer showed up during a comic skit on the show that featured Handler’s panelists discussing his autobiography in a book club.
US funnywoman Heather McDonald jokingly dropped to the floor, in mock fear that “Fiddy” was pulling out a gun.
But instead the hip-hop star whipped out a copy of his book and sat down to join the group.
The Chelsea Lately star, 35, remained tight-lipped about whether she is romantically involved with “Fiddy”, real name Curtis Jackson.
“There are all sorts of rumours going around about myself and a certain rapper with a number in his name,” she said during her show, neither confirming nor denying the speculation.
The pair first hit the headlines last month after they were spotted looking cosy at a New Orleans nightclub.
But Handler denied the rumours soon after on her Twitter page, writing: “Everyone calm down. I met with Mr Cent about a potential project. There’s nothing to report yet. I’ll let you know if there is.”
However, they have been spotted together since then, sparking fresh rumours that they are dating.