The London pop rockers - made up of frontman Chris Martin as well as Guy Berryman, Jonny Buckland and Will Champion - were aired 40,000 more times across UK radio and TV than classic rockers Queen, who came in at number two, according to the company.
Coldplay's biggest track was 2008's number one hit Viva La Vida, and was followed by their other hits Paradise, Clocks, Something Just Like This and Adventure Of A Lifetime.
The band, started in the 1990s, have enjoyed enduring popularity, and recently became the first act to headline Glastonbury five times.
Since the release of their debut number one record Parachutes in 2000, the band has had a total of nine chart-topping records.
"This country has produced some of the most iconic and successful bands of all time, so documenting them is a perfect way to mark this year's National Album Day," PPL chief executive Peter Leathem said.
"Including groups from across the last 60 years, this list is a reminder of the strength and depth of British music through the decades.
"Coldplay are fitting owners of the number one spot - few artists can claim to have had such a presence on UK radio and TV since 2000."
At third on the list was boyband Take That, while The X Factor's girl group Little Mix followed at number four, and The Beatles came in at number five.
Manchester rockers Oasis were at number six, while the The Bee Gees came in at number seven, Welsh group The Stereophonics reached number eight, pop duo The Eurythmics were ninth and The Rolling Stones rounded out the list at number 10.
The chart uses data from PPL licences being issued, which allows the use of recorded music on radio, TV and in public places such as shops, bars, restaurants, gyms, offices and warehouses in the UK.
Airplay reporting also comes from such broadcasters and public performance venues.
PPL also noted that despite one of Queen's biggest hits Bohemian Rhapsody being released in 1975, their music has endured, just like The Bee Gees and 1980s bands Duran Duran and The Police - who came in at number 12 and 14, respectively.
Many of the groups have reformed recently including Sugababes, and Oasis announced last month that there will be new touring dates with Liam and Noel Gallagher set for next year.
The list of most played British band's in the 21st Century:
1. Coldplay
2. Queen
3. Take That
4. Little Mix
5. The Beatles
6. Oasis
7. The Bee Gees
8. The Stereophonics
9. The Eurythmics
10. The Rolling Stones
11. Clean Bandit
12. Duran Duran
13. Sugababes
14. The Police
15. Simply Red
16. Snow Patrol
17. Electric Light Orchestra
18. Keane
19. Wham!
20. Texas