The Affair star took to Instagram on Monday to celebrate his 40th birthday with a sweet, smiling selfie, thanking his friends for making the last year one of the best.
"40 trips around the sun. What a year this has been," Jackson captioned the pic. "Thank you to the new friends and old who have made this the best trip yet."
One of those new friends might be TV host Alyssa Julya Smith, whom Jackson was rumored to be dating earlier this year. While the two were spotted together in New York City last week, a rep for the actor said reports of their rumored romance were "not accurate."
Jackson has come a long way since he captured Joey's heart on Dawson'sCreek, but he'll always be Pacey Witter.
The Dawson's Creek cast, including Jackson, Katie Holmes, James Van Der Beek, Michelle Williams, Busy Phillips, Kerr Smith, Meredith Monroe and Mary Beth Piel, reunited in March for Entertainment Weekly, one of their first reunions since the series ended in 2003.