The two musicians were both in the Irish city this week on tour with the 'Gimme Shelter' rockers kicking their 'No Filter' concerts at Croke Park Stadium on Thursday night and Ed playing shows at Phoenix Park.
After realising they would be crossing paths the two stars made a date, and Ed, 27, took the chance to pick Mick's brain on achieving longevity in the biz as The Stones have been going strong since the '60s.
A source told The Sun newspaper: "They're both great networkers who love music and enjoy talking about life in the business. So when they realised their tours were crossing over in Ireland, they decided to get together for lunch, picking somewhere very posh but very private to do it out of the way given they are two of the world's most recognisable stars.
'Honky Tonk Women' guitarist Keith Richards initially had doubts about what Ed was doing as a musician when he saw him sing alone using loop pedals and effects to boost his guitar sound, but after watching him perform properly he was blown away by his talent.
Keith, 74, previously said: "Ed Sheeran was amazing, when he played with us. I thought it was going to be a joke because he had to go on at bloody great big stadiums in America and he came on with his two amps and his other things. But he was great, it was incredible to see actually.
"He's so clever - to be able to do that."