The UFC superstar shared the great news following a visit to the doc's office in L.A. on Thursday ... giddily explaining that he's been cleared to ride a bike nearly a month earlier than medical experts initially expected.

"Five weeks, five days since the surgery and they told me I wouldn't be able to cycle until eight weeks," Conor said. "And, he just told me just here today that I can cycle again!"

It's a very positive update from the 33-year-old ... 'cause back on July 10, he snapped his leg in gruesome fashion in his fight against Dustin Poirier that many believed could alter his life permanently.

You'll recall ... the leg bent in a way no leg every should -- and he needed hours of surgery just days later to repair the damage.

But, Conor's been in great spirits ever since going under the knife ... and he showed us again Thursday that he's genuinely pleased with how the injury is progressing.

"I can cycle again, my man!" Conor said before driving off from his doctor appointment. "Three weeks ahead of schedule!"

As for who he wants to fight when ultimately makes his return ... Conor clearly ain't ahead of schedule in that department -- telling us, "we'll see what happens."