Lady GaGa's latest single Bad Romance is the current UK number one
Lady Gaga's single Poker Face and Susan Boyle's debut album I Dreamed A Dream were the UK's biggest-selling records of last year.
Lady Gaga's debut single Just Dance also made it to number three in the singles chart of 2009.
Boyle's debut album sold more than 1.5m copies in six weeks. Lady Gaga's single Poker Face shifted 800,000 copies.
"It's a phenomenal achievement for them both," said Martin Talbot of the Official Charts Company.
TOP 10 OFFICIAL SINGLES OF 2009
1. Poker Face - Lady Gaga
2. I Gotta Feeling - Black Eyed Peas
3. Just Dance - Lady Gaga
4. Fight For This Love - Cheryl Cole
5. The Climb - Joe McElderry
6. In For The Kill - La Roux
7. Boom Boom Pow - Black Eyed Peas
8. Killing In The Name - Rage Against the Machine
9. Bad Boys - Alexandra Burke featuring Flo Rida
10. Meet Me Half Way - Black Eyed Peas
Lady Gaga's album, The Fame, was the second-biggest selling album of 2009 in the UK.
Sunny side up
"Lady Gaga and Susan Boyle have captured the public imagination and made the charts their own in less than a year," said Mr Talbot.
Lady Gaga also laid claim to the the first singles chart of 2010, as Bad Romance returned to the number one spot.
X Factor winner Joe McElderry's single The Climb went down to number two.
In this week's album chart, Paolo Nutini's Sunny Side Up returned to number one, having first made it to the top spot in June last year.
Lady GaGa's The Fame is at number two, with Susan Boyle's I Dreamed A Dream in third place.