The Outlander star took part in the Distinguished Gentlemen's Ride across the capital, as he raised cash for men's mental health and cancer charities.
He posted a video and photo of himself sitting atop the police motorbike, captioning it on Instagram: "Thanks to @policescotlandofficial for keeping us safe on the @gentlemansride , a great day out! (and for allowing me to be a total big kid)"
He pointed to the blue flashing lights as he sounded the siren, looking pretty pleased with himself as he donned a full brown tweed suit, and bow-tie.
Fans flocked to his social media comments to gush over the stars stunning look and his new whip.
One Instagram user wrote: "Imagine being pulled over by Constable Heughan!"
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Another said: "Look at you flashin the blues and twos....love it. Thanks for the like, which I've been told was in the Express. My hubby won't stop slagging me off about it."
A third wrote: "What an amazing experience for you! So happy the ride was safe and successful and that you had the chance to bring awareness to this special cause."
Further comments read: "Lol, like a kid in a sweet shop", and "Well, if this acting thing doesn't work out..."
The 42-year-old, most known for his portrayal of Jamie Fraser in the Scottish fantasy series, is still fundraising for donations towards prostrate cancer research, and men's mental health.
The Distinguished Gentleman’s Ride unites classic and vintage style motorcycle riders all over the world to raise funds and awareness for prostate cancer research and men’s mental health.
The Distinguished Gentleman’s Ride was founded in Sydney, Australia, by Mark Hawwa.
Sam, an avid lover of motorbikes, officially passed his test in 2020, after it was put on hold due to the coronavirus pandemic.
You can support Sam's fundraiser here.