A £5m grant from a new Heritage Lottery Fund (HLF) programme will be used for the regeneration of the Harland and Wolff headquarters building and drawing offices in Belfast.
The money is earmarked to support the restoration of the Grade B+ listed building into a boutique hotel.
The development could create 109 jobs.
HLF has also allocated £784,000 to transform the Northern Counties building in Londonderry into a hospitality-based complex.
The Northern Ireland projects are among the first in the UK to benefit from the HLF's new funding programme, Heritage Enterprise.
The Harland and Wolff building on Queen's Island has been vacant since 1989 and has been considered "at risk" for almost a decade.
It was once the control centre for the largest shipyard in the world where more than 1,000 ships, including the White Star Olympic Class liners - Olympic, Titanic and Britannic - and naval warships such as HMS Belfast, were designed.
The most historically important rooms, such as the drawing offices, board room, telephony room and entrance lobby, will be developed as spaces for public use.
Nicky Dunn, chair of Titanic Foundation Ltd, said: "We are delighted that our application to HLF's Heritage Enterprise fund has been successful.
"The former Harland and Wolff headquarters building and drawing offices are one of the most authentic and tangible links to narrating Belfast and Northern Ireland's maritime and industrial heritage.
"The Titanic Foundation has worked in partnership with Titanic Quarter Ltd to develop a new use for what we regard as a national icon.
"We are committed to maximising both the heritage and commercial opportunities, promoting preservation and public access as well as tourism and wider economic benefits."
HLF chief executive Carole Souter said: "Through Heritage Enterprise we have inspired creative new partnerships between social and private enterprise to rescue and return to use some of our most neglected historic buildings.
"This multi-million pound investment in Northern Ireland's heritage will enable two iconic local buildings to be brought back to life and have their potential as tourist assets and catalysts for wider regeneration achieved, and we are delighted to be involved."
The Northern Counties in Derry is located on Bishop Street within the city's conservation area and was originally developed as two buildings before it was remodelled around the year 1902.
Its previous life included time as a private member's club, when it was an base for the business and civic leaders of the city and as such was not accessible to the general public.
Social and demographic changes in the city resulted in the closure of the club and it was used for office accommodation before becoming vacant in 2006.
The refurbished building will have the potential to create approximately 45 new jobs and significantly improve the tourism offer in the city centre.
Helen Quigley, managing director of the Inner City Building Preservation Trust, said: "This is an exciting project that will substantially contribute to the renewal of the building and regeneration of the area and is part of our overall investment strategy for projects within the old walled city part of the city centre."
The HLF investment is part of an UK-wide funding package worth £12m, and part of a wider investment of at least £125m over the next five years.