James Van Der Beek would have celebrated his 49th birthday Sunday, and his wife Kimberly is marking the milestone with a heartbreaking message.

Kimberly took to Instagram to post a photo of the two together outdoors, writing, "Would be your 49th birthday today. And I'm missing you tremendously."

We broke the story ... the former "Dawson’s Creek" star died February 11 after battling stage 3 colorectal cancer. He revealed his diagnosis in late 2024, sharing that he was undergoing treatment while focusing on time with his loved ones.

He's survived by Kimberly and their six children -- daughters Olivia, Annabel, Emilia and Gwendolyn, and sons Joshua and Jeremiah.

The birthday tribute marks another emotional moment for the family following his passing. What would have been a celebratory day is now one filled with remembrance.