Peter Tripp conducted what was probably the most famous DJ "wakeathon" back in 1959. I wrote a post describing the incident in 2009 here. The short version is that he stayed awake for 200 hours and went temporarily insane. Remember 200 hours is over eight straight days awake. Despite the obvious dangers the march of dimes sponsored a contest that year pushing DJs to greater depths of sleep deprivation. In most circles this is considered torture. At least it raised money to fight polio.
Before 1957 I find a number of WWII war bond drives that reached or approached the 24-hour mark. these mostly intimate but do not confirm that the host was awake for 24 hours. I consider these marathon events ta precursor to this broadcasting tradition. Likely candidates on this list include Kate Smith (18 hours), Eddie Canton (16 hours) and a large number of uncredited local broadcasters. Dr. Louis Jolyon West, a former USAF psychologist also records two Oklahoma City area DJs who went 168 hours in 1954 but I've never identified the DJ or the station.
Below is a running list I have of print-cited DJ marathon records. There is no single canonical source, so I've tried to caveat each claim where I can. Some references are short on critical details. I note them anyway. They are in more-or-less chronological order. I'll add to this list as research continues. Feel free to contribute.
1957 Dave Clarke - KVI-AM - 104 hours, 3 minutes
1958 Loren Valentine - KAKE-AM - 175 hours Wichita
1958 Mort Crowley - KWK-AM 54 hours, 14 minutes (sometimes cited as KEK-AM)
1959 Stan Major - WIRL-AM - 180 hours (some versions say 210 or even 215 hours)
1958 Dave Hunter - WMOP-AM - 187 hours
1959 Red Evans - WTAL-AM - 190 hours, 43 minutes
1959 Peter Trip - WMGM-AM - 201 hours, 10 minutes
1959 Jo Warner - KYTE-AM - 203 hours (sometimes listed as 220 hours)
1959 Dave Hunter - WZRO-AM - 225 hours (sometimes cited as WERO)
1959 Jerry Teel - KSTN-AM - 245 hours, 6 minutes
1959 Tom Rounds - KPOI-AM - 260 hours
1959 Jim Austin - WBOW-AM - 229 hours 30 minutes (multiple attempts)
1959 Robert Murray - WAIK-AM - 231 hours, 11 minutes
1959 Gerald Edward Phillips (Mel Kent) - WYDE-AM - 195 hours
1960 Jim Austin - WBOW-AM -231 hours
1960 Rick Michaels - WBRB-AM - 243 hours
1961 Don Redfield - WBSR-AM 68 hours, 45 minutes
1961 Jim Rud - KXGO-AM - 137 hours
1961 Snuff Garrett - KSYD-AM - 110 hours
1961 Dave Diamond - WKGN-AM - 60 hours
1961 Lou Brink & Larry Wayne - WEZL-AM - 142 hours, 9 minutes
1962? Rick Michaels - WBRB-AM - 230 hours
1963 Tom Mathis - WIBC-AM - 100 hours
1964 Khan Hamon - WKDA-AM - 124 hours
1964 Genie Chance - KFQD-AM - 59 Hours
1965 Rhett Evers - WTFM-AM - 240 hours
1967 Keith Ashton - Radio Hauraki - 65.5 hours
1968 Ron Waddel - CKDM-AM - 80 hours, 25 minutes
1970 Steve Warren - WAMS-AM - 110 hours
1988 Bob Rivers - WIYY-FM - 258 hours (slept between songs)
2001 Glen Jones- WFMU-FM - 100 hours
2002 Greig Daines - Hospital Radio - 73 hours (UK)
2002 Matt Fulton - 2MCR - 103 hours 14 minutes (Australia)
2003 Kristian Bartos - WOW - 103 hours (Sweden)
2003 Arulanantham Suresh Joachim - CMR-FM (Canada)- 120 hours
2004 Charlie Welch - WJUC-FM - 107 hours
2005 Dave Plotkin - WPRK-FM - 110 hours
2006 Stephano Venneri - BBSI - 125 hours (Italy)
2009 Stefano Venneri - BBSI - 183 Hours (Italy)
2010 KeKe Luv - KSAS-FM - 199 hours (with 15 minute break every 8 hours)
2011 Chris Moyles & Dave Vitty - BBC - 52 Hours (UK)
2012 KeKe Luv - KSAS-FM - 175 hours
2012 Peter Van de Veire- MNM - 185 hours (Belgium) (with naps)
2014 Giel Beelens - 3FM - 198 Hours (Netherlands)
2014 George Willis & Andy Cox - Shock Radio - 85 hours (UK)
2015 Joe Madison - XM Radio - 52 Hours ( 3 breaks per hour)