The pair only started competing together at the start of this year but have returned with medals from every international event they have taken part in.
They continued that form at Ponds Forge by scoring 444.48 points, which was only two points off their best.
They finished a massive 132 points ahead of Sheffield’s Elliot Beeden and Conrad Lewandowski, who were the only other pair in the final.
“I think that competition was steady for us,” said Plymouth-born Daley. “It’s what you want to do at a national championships.
“It was our last competition before Rio and only two points down on our best score. We’ve competed well at pretty much every competition we’ve been to which gives us confidence.”
Plymouth Diving’s Goodfellow added: “We have bonded as a pair pretty well and we’ve only been doing synchro for under a year and the performances speak for themselves.”
Daley revealed afterwards that Goodfellow would be moving in with him in London for six weeks so they can train together every day at the Aquatic Centre in preparation for the Olympics.
Meanwhile, Plymouth Diving’s Tonia Couch and Leeds’ Lois Toulson scored 293.22 points in the women’s synchro event.
They were the only pair taking part, with everyone else concentrating on trying to secure individual Olympic places.
“It’s really exciting for us to be British Champions,” said Couch. “We were obviously the only pair in it but we competed against the boys and we know we have more to give.”
Couch was set to compete in the individual event on Saturday, along with her Plymouth team-mates Sarah Barrow, Robyn Birch, Victoria Vincent and Shanice Lobb, however, she now no longer appears on the start list.
The city star’s absence does open the door for Barrow to try and secure a place on the Great Britain Olympic team. The pair finished first and second at the National Championships earlier this year.
GB have two spots available in Rio in the women’s 10m, one which should go to Couch, with the other place going to the winning of this weekend’s event, providing they achieve the minimum qualification points.
Plymouth Diving’s Alfie Brown, Aidan Heslop and Alex Kostov will also be in action on Saturday in the three-metre event.