US restaurant company Jack in the Box has announced a leadership transition, with its board of directors appointing Mark King as executive chairman and interim CEO, effective immediately.

Succeeding Lance Tucker, King joined the board in November 2025 and became chair in March 2026. In his interim role, he will focus on the company’s transformation efforts.

The fast food restaurant chain has also appointed Alan Smolinisky as lead independent director.

The transition follows weaker second-quarter fiscal 2026 (Q2 FY26) results for the company.

For the quarter ended 12 April, Jack in the Box reported total revenues of $254.3m, down 4.3% from $265.7m in the prior-year period.

The company attributed the decline to reduced same-store sales and a lower number of restaurants.

Same-store sales decreased 3.8% during the quarter. Franchise same-store sales fell 3.9% while company-owned same-store sales declined 2.8%.

Jack in the Box said its restaurant count was flat in the quarter, reflecting nine restaurant openings and nine closures.

Diluted earnings per share from continuing operations also decreased to $0.65, down from $1.09 a year earlier.

Commenting on the results, Mark King said: “Second quarter results did not meet expectations; however, trends have improved into the third quarter. Jack in the Box is an iconic brand, and I'm eager to dive in with our passionate team and franchisees to further improve operating results.

“After being on the board and now as interim CEO, my excitement for the potential of this brand has only grown.

“We plan to accelerate our 'JACK on Track' commitments as we strengthen our foundation to support sustainable, long-term growth.”

Earlier this year, Jack in the Box selected Restaurant365 as its back-office inventory platform. The solution was rolled out across all 2,128 company-operated and franchised restaurants in the US.