The 29-year-old from Leeds – an Olympic finalist in the 800m in Tokyo earlier this summer, when she finished seventh – picked up the baton with GB&NI down in sixth at the start of the third leg on Sunday.
Hannah Nuttall’s solid start had the British team sixth as she handed over to Mansfield’s Luke Duffy, who maintained the team’s position, 12 seconds down on then-leaders Ireland.
But the experienced Bell underlined why she had been named as captain for the meet, as she chewed up the ground.
By the end of her run she had opened up a near five-second advantage for Ben West, whose aggressive start to the final leg was rewarded with victory in 18:01.
After the race, team captain Bell said: “I am so happy for this team, to win gold is a great achievement for this young squad.
“Everyone played their part in making this happen today so I’m very proud of them.
“This (Euro Cross) is a key part of my winter season – only the relay I should say, I’m not running 8km.
“So I have a lot of experience in these teams now and it is great to be a part of this team and race in the relay.
“I’m very proud to have been part of a gold-medal winning team.”
The relay gold caps a stellar year for Bell who broke her personal best over 800m on the track on numerous occasions and also ran through two rounds to make the Olympic final despite only being a late call-up for Team GB.
Individual gold medals were clinched by Megan Keith and Charles Hicks as the 40-strong British contingent topped the medal table in Fingal-Dublin.
Keith continued her stellar cross country form by taking the women’s under-20 contest by the scruff of the neck and holding on in the closing stages for the British team’s first individual gold in the event since 2017.
Hicks led the men’s under-23 race almost from gun to tape and had to produce a huge effort in the final incline to hold off Darragh McElhinney (IRE) and Ruben Querinjean (LUX) for his first individual medal in a British vest.
Jemima Elgood of Ilkley helped the Under-23s team win bronze.