Ryan Leith, a port controller with Lerwick Port Authority in Shetland, jumped into the water of Lerwick Harbour to help the man.
Local musician Maurice Henderson and Police Scotland temporary sergeant Victoria Duthie were also involved in the rescue.
The incident happened at around 23.30 on 24 November 2016.
Mr Leith has been presented with the Royal Humane Society's Testimonial on Vellum, one of the society's top awards which recognises risk taken by an individual in a rescue.
Mr Henderson and Ms Duthie received Certificates of Commendation.
Dick Wilkinson, secretary of the Royal Humane Society, said: "Ryan Leith was undoubtedly the right person in the right place at the right time.
"Thankfully, although it was dark and conditions were not particularly good, he spotted what was happening and took immediate action.
"And, thanks to the efforts he, Victoria Duthie and Maurice Henderson put in, a life was saved.
"As it was, the three of them worked marvellously as a team. All three richly deserve the awards."
Mr Leith had just started his night shift as a port controller when he saw a woman on the edge of Alexandra Wharf about 120m away and a man's head appear above the edge and then disappear.
Alerting police and the Coastguard, he ran to the site and found the man and woman in difficulty.
He lowered a life ring to the man, who was now in the water, while the woman had climbed back on to the jetty.
The man grabbed the ring and was being pulled towards a ladder by Mr Leith when he dropped the ring and grabbed fender tyres on the wall, but then became unresponsive.
Mr Henderson, who was driving past, was flagged down and Mr Leith then jumped into the water to support the man while Mr Henderson towed them to the ladder.
All three rescuers helped the man up to the quay from where he was taken by ambulance to hospital and later discharged.
After going home for a shower, Mr Leith returned to duty at 01:15.
The presentations were made by Lerwick Port Authority chairman Brian Anderson, on behalf of the Humane Society in a ceremony on Saturday.
Three people have received bravery awards after they rescued a man from a harbour in the dark, saving his life.