The What's Your National Treasure initiative asks people to choose from a range of well known and loved venues, landmarks and facilities in the UK as well as name their top star from England, Wales, Scotland and Northern Ireland.
A shortlist of 20 famous faces have been chosen due to their achievements as recipients of National Lottery funding or for their support of projects that have received funding.
They include Colin Firth, Jessica Ennis and Stephen Fry in the England category, and Sir Chris Hoy, James McAvoy and Lorraine Kelly as representatives of Scotland with five celebrities to choose from in each of the four countries.
There are 12 places of interest to select from in each nation including Ben Nevis, the Queen Elizabeth Olympic Park in London, Cardiff's Millennium Stadium and the Giant's Causeway in County Antrim.
The winning personality and place for each country will be announced from the list of 68 later this year.
The National Lottery has launched the search as part of its twentieth anniversary celebrations this year as the final phase of its Just Imagine campaign, which began in January to raise awareness of the impact that £31 billion in funding has had on the UK since the first draw.
Director of the National Lottery Promotions Unit, Vicki Kennedy, said: "We're asking National Lottery players and members of the public to decide which iconic places and famous faces best represent the enormous impact of National Lottery funding across society over the last two decades.
"This is a fun way for people to show their backing for the projects they care most about and also gives us a great chance to celebrate the massive impact National Lottery players have on our society across England, Wales, Scotland and Northern Ireland.
"The UK is packed full of national treasures and we're proud that National Lottery funding has been able to benefit so many of them."
Votes can be cast on Facebook.com/LotteryGoodCauses from 9am today until midnight on May 27.