TV presenter and columnist Peaches Geldof was the most popular term, according to new research from Microsoft's search engine Bing.
The 25-year-old died in April after suffering a heroin overdose at her home in Wrotham, Kent.
Hollywood star Robin Williams came second on the list after he took his own life in August.
Bing says nearly half of all British searches for the comedian came from smartphones.
In third place was Oscar-winning actress Jennifer Lawrence, who has been in the spotlight for both professional and personal reasons this year.
The 24-year-old plays the lead role in the The Hunger Games.
Its latest instalment Mockingjay - Part One took $123m (Â£79m) in its opening weekend in the United States.
Over the summer naked images of Jennifer Lawrence were leaked online, something she later called "a sex crime".
Fast & Furious actor Paul Walker, who was killed in a car accident in November 2013, completed the top four.
Newly-engaged Wimbledon champion Andy Murray was the UK's most searched-for sportsman in 2014, followed by South African Olympic and Paralympic athlete, Oscar Pistorius, who was jailed in October for killing his girlfriend.
In the music world, One Direction and Justin Bieber captured the most online attention this year.
Follow @BBCNewsbeat on Twitter and Radio1Newsbeat on YouTube
The death of the world's biggest celebrities made them some of Britain's most searched-for stars in 2014.