Long, who was the first regular female presenter on Top Of The Pops, died at home on Christmas Day following a short illness, her agent said.
Across a 40-year career, she hosted slots on flagship stations such as BBC Radio One, helped launch the careers of artists including Amy Winehouse and led coverage of major music events such as Live Aid.
BBC radio DJs Greg James and Adele Roberts, TV host Carol Vorderman, Peter Hook of Joy Division and New Order, rock band The Subways and The Charlatans frontman Tim Burgess were among those sharing tributes.
James described Long as a “truly brilliant radio person”.
He said: “She was so kind and sweet to me when I was on earlies on R1 and she was on R2 nights at the same time.
“She picked the greats and got them in session before other DJs had even heard of them. She was such a laugh as well.”
Roberts hailed Long for forging a path for women in the media industry.
She said: “RIP Janice Long. Thank you for everything you did to inspire others and open doors for other women and radio presenters to prosper.”
TV host Vorderman echoed her comments, writing on Twitter: “As a woman in the industry, I truly admired her as the first woman ever to have a daily show on Radio One @BBCR1. We’re in a state of disbelief to be honest.”
Merseyside band The Coral, who received early support from Long, said: “Sad to hear the news about Janice Long passing.
“She was great to us and like the best broadcasters, talking to her was always easy, like catching up with a friend. RIP Janice.”BBC director-general Tim Davie said: “Janice Long was a stellar presenter, who was loved and respected across the industry, and her passing is a huge loss to music, broadcasting and the BBC.
“Over 40 years she blazed a trail across Radio 1, Top Of The Pops, Radio 2 and 6 Music to name just a few, before building a wonderful show and loyal following on BBC Radio Wales. She will be missed by her fans, listeners and colleagues.”
Long grew up in Liverpool, the older sister of late entertainer Keith Chegwin.
After working as cabin crew and in telesales, Long started her broadcasting career as a station assistant at BBC Radio Merseyside in Liverpool in 1979.
She became well known after joining Radio 1 in 1983, becoming the first female to have her own daily show on the station.
Long later became the first woman to be a regular presenter of Top of the Pops where she hosted the show for five years, and was one of the main presenters of the Live Aid concert in 1985.
Long was an early supporter of future stars such as The Smiths, Frankie Goes To Hollywood, Primal Scream, Adele, Amy Macdonald and Winehouse.