The deal was first officially announced in October, with regulatory processes to be completed before the sale could be finalised.
On Monday, it was confirmed that both UTV and UTV Ireland were now under ITV ownership.
“I am delighted to welcome everyone there to the ITV family,” Chief Executive Adam Crozier said.
“We recognise the strength of UTV in Northern Ireland. UTV Live is one of the most successful – and highest rating – news programmes in the whole of ITV.
“We are committed to maintaining and strengthening the news service and UTV’s wider programming output.”
UTV in Northern Ireland was launched in 1959, broadcasting many of the region’s most watched programmes - including its flagship news programme UTV Live - and launching the careers of many household names, such as Gloria Hunniford and Eamonn Holmes.
It was the first commercial television channel on the island of Ireland when it went on air and now employs over 140 staff.
Speaking about UTV Ireland, which was created in January 2015, Adam Crozier added: “The team has done a great job in establishing UTV Ireland and shaking up the Irish market place in the process.
“In just over a year on air, the channel is already running second in the market in ratings terms on a regular basis.
“This is a significant achievement and one we look forward to building upon with the team.”
Michael Wilson, who remains as Managing Director of UTV and UTV Ireland, said: “I am very proud to be surrounded by a highly talented and enthusiastic team who work for UTV Television.
“Their dedication has ensured the success of UTV in this marketplace - UTV Ireland is now reaching more than 2.3 million people every week after just a year on air, and UTV remains by far the most watched channel in Northern Ireland.
“These are significant achievements in a highly competitive market and ITV has the scale and capabilities to build upon the future potential for both UTV channels, maximising audiences across all platforms.”
UTV and UTV Ireland’s former parent company UTV Media plc will now change name as the brand was sold to ITV as part of the deal.
The company, which retains its radio operations – including U105 in Belfast and talkSPORT – and digital operations Tibus and Simply Zesty, will operate as the Wireless Group plc with immediate effect.
Copyright © 2016 UTV Ltd. All rights reserved.