However, the native New Zealander moved on from the world of F1 last year, as she prepared for a fresh challenge across the pond.
Hamilton insists the pair remain good friends, as Cullen proceeded to enjoy a series of adventures during her sabbatical from motorsport.
Angela Cullen star makes IndyCar switch
Since leaving F1, she has joined Armstrong’s camp as his trainer in IndyCar, and appears to be thriving in her new role.
The fellow Kiwi competed for Chip Ganassi Racing throughout the 2024 season, where he placed 15th in the overall standings.
Armstrong has hailed the impact Cullen has had on his career, applying her expertise from Hamilton’s championship years, which has translated into some of his results - including a career-best finish of P3 at the Detroit Grand Prix.
However, Armstrong will move on from Chip Ganassi Racing next year, and instead race for Meyer Shank Racing, after his former team downsized from five cars to three under the new charter system.
The 24-year-old will partner Felix Rosenqvist for 2025, with Cullen set to enjoy the new scenery alongside him.
“I’m very proud to be joining Meyer Shank Racing in 2025,” Armstrong said.
“I had a great feeling when I met both Mike Shank and Jim Meyer, their passion for performance and meticulous work ethic was obvious from our first conversation and I want to thank them both for this opportunity.
“This year I got closer to where I want to be performance-wise, including oval racing for the first time and I’m looking forward to continuing to push up the order with MSR.
“We want to be at the front, fighting for wins and I believe we have the recipe to do it.”