The presenter, who is married to Ronnie Wood's son Jesse, announced in February (15) she was leaving BBC Radio 1 after nearly a decade so she can focus on motherhood as she is expecting her second child.
Martin honoured the day in song and penned a track for Cotton called Gone But Not F Cotton. Lyrics include, "Have to tell her thanks for the records she played, Thanks for introducing us to Lana Del Rey."
Other stars took to Twitter.com to pay homage to Cotton and thank her for her many years on the airwaves.
Smith wrote on the microblogging site, "Sorry its your last day @Fearnecotton! Will miss your sweet voice in my ears every day xx thank you for your support" while Sheeran adds, "Lots of love to @Fearnecotton and all the support she's given me and so many others on @BBCR1. You are the bestest evah (sic)."
Maroon 5 thanked the star, writing, "Always a blast in the @BBCR1 Live Lounge w/ (with) @fearnecotton. Thanks for all the love. We'll miss you! #FarewellFearne."
British rockers Kasabian shared, "Thank you so much for all your support over the years, you are the real deal. ramble on sister xx" and pop star Tulisa Contostavlos wrote, "Have an amazing last show babe @Fearnecotton @BBCR1"
Cotton and Wood, who got married last year (14), share a two-year-old son called Rex Rayne Wood.