Instead, he'll be attending the wedding of his ex-girlfriend and longtime friend, Jecca Craig, who is saying "I Do" to Jonathan Baillie at her family's Lewa Wildlife Conservancy in Isiolo, Kenya, on Saturday, a source confirmed to ET.
Although Middleton reportedly won't be in attendance, Craig has proved she and William are just friendly exes. After all, she did attend the Duke and Duchess of Cambridge's royal wedding in 2011!
ET has learned that William is "in Kenya this weekend on a private trip" scheduled around Easter, as confirmed by Kensington Palace.
And it looks like he's already making the most of his trip! On Thursday, William met with Kenyan President Uhuru Kenyatta.
"Our deliberations revolved around conservation, security and defence," Kenyatta wrote in a post on Twitter, which was re-posted by Kensington Palace.
Photos: Meet Prince William's ex Jecca Craig
William also paid a visit to Tusk Trust, a conservation charity that aims to protect wildlife and promote education throughout Africa. The future king of England serves as their royal patron.
"Great to have #PrinceWilliam witness elephant & rhino conservation in action today with KWS vet and rangers in Kenya," a tweet from the Tusk Trust read.
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Once William returns home to his family, he'll have another exciting moment to celebrate -- Queen Elizabeth's 90th birthday!
The Queen rings in her milestone birthday on April 21, and in her honor, the royal family has been sharing their fondest memories of her, including an adorable nickname invented by Prince George.
"George is only 2½ and he calls her 'Gan-Gan,'" the Duchess revealed in ITV's Our Queen at Ninety, her first solo interview since tying the knot with William. "She always leaves a little gift or something in their room when we go and stay, and that just shows her love for her family."
PHOTOS of Kate and Will through the last year