That's what insiders are whispering after the longtime pals got more than cozy at two different La-La Land events.
The unlikely pair coupled up at the Ralph Breaks the Internet premiere on Nov. 6 and again three days later when Emmy winner Silverman, 48, received a star on the Hollywood Walk of Fame.
"They've known each other a long time and always been close," the source spilled. "But Jon was in a longtime relationship until a couple of years ago."
As Radar reported, Hamm, 47, saw his 18-year romance with Jennifer Westfeldt end in 2015.
"The door then opened for Jon and Sarah," the source said. "They're comfortable with one another — so why not?"
We pay for juicy info! Do you have a story for RadarOnline.com? Email us at firstname.lastname@example.org, or call us at (866) ON-RADAR (667-2327) any time, day or night.