The 25-year-old centre-back missed Boro’s Championship opener at Millwall to complete negotiations at Turf Moor.
The Clarets, who had made two previous bids for Gibson, are matching the club record fee they paid Leeds United for Chris Wood last summer.
Speaking after the 2-2 draw at The Den, Boro chief Tony Pulis said: “He’s going, it’s agreed, it’s done and we want to thank Ben, an absolutely fantastic professional.
“In the six months I’ve had at this football club he’s as good a professional as I’ve ever worked with and I spoke to Sean Dyche and Dychey’s got a real, top, top player.”
Boro are set to land Waghorn for less than Ipswich’s initial £8m asking fee, pipping Sheffield United, who had made a £5m bid, and Derby County for his signature. The 28-year-old was left out of Ipswich’s squad for the Championship opener against Blackburn.
Having missed out on Brighton midfield man Oliver Norwood, Hull City are interested in signing Sunderland’s Lee Cattermole, 30, on loan.
The Tigers need cover following the departures of David Meyler and Seb Larsson and Cattermole certainly has the experience, having made 225 appearances for Sunderland.
Hull are also said to be interested in Leeds United target £3.6m-rated striker Mbaye Diagne, from Turkish club Kasimpasa.
Northern Ireland international George Saville, 25, was watched by Sheffield United scouts on Saturday.
The Millwall midfield player shone against Middlesbrough but he is also wanted by Leeds United and Aston Villa.
The goal-scoring midfielder started out at Chelsea and joined Millwall for a bargain £350,000 from Wolves last year.
Leeds could be taking another Manchester City youngster on loan.
Lukas Nmecha, 19, is set to follow Jack Harrison to Elland Road.
Huddersfield Town and Tottenham are set to miss out on Eintracht Frankfurt winger Ante Rebic, who is set to join Sevilla for £19m.
Sheffield Wednesday supporters could hear if rumours are true that they have been placed under a transfer embargo for breaching financial fair play rules when chairman Dejphon Chansiri attends a fans forum at Hillsborough tomorrow.