The lure of Championship football swayed the 26-year-old striker in the direction of Wales over League One Sheffield United, who also wanted the 25-goal forward.
“I couldn’t have signed for a better club in Cardiff,” beamed Doyle, after transferring from Chesterfield on a two-and-a-half year deal.
“They have massive support, Premier League facilities and very ambitious. I got the call this morning and was delighted to come down and finally get it sorted after all the speculation.
“It (an Ireland call-up) is on the back of my mind. It would be a dream to play for my country but I’ve got to play regularly for Cardiff first.”
Derry City winger Michael Duffy sealed a dream move to Celtic for around €150,000. The 20-year-old represented the Republic’s U18s in 2012 and, although he’s since earned U21 caps for Northern Ireland, Duffy may opt to switch back in time for the campaign Noel King’s side are to kick off later in the year.
Paul Heffernan, a former team-mate of Doyle’s at Hibs, left Easter Road to join SPL side Dundee, from where Irish U21 Phil Roberts departed in the opposite direction to link up with Championship club Alloa on loan.
Back in England, Plymouth recruited Anthony O’Connor from Blackburn having played the Corkman 26 times during a loan stint that ended a fortnight ago.
Former Chelsea trainee Conor Clifford left Southend for Conference title contenders Barnet. Keith Andrews ended a nightmare season to rejoin former club MK Dons from Bolton.
Staying put at Celtic is fellow Leesider Eoghan O’Connell, who extended his contract at Parkhead by another two years.
Ireland U21 striker Conor Wilkinson was once again loaned to Oldham from Bolton, this time until the end of the season.
Brendan Moloney from Beaufort in Co Kerry had his loan from Yeovil to Northampton made permanent.