The international road racer, from Louth, also took a second and third place, as well an eighth spot to win the Joey Dunlop TT Championship for the second time in three years.
His exploits helped the Smiths Racing team to the team award for the third year in succession.
Having already won the Superbike race at the beginning of the week, the 32-year-old joined a select band of riders to win two races in a day around the 37.73-mile Mountain Course.
He followed up victory in the second Supersport race by winning Superstock race.
With racing again disrupted by the weather, there was no track action until Thursday when Hickman was back out in the second Supersport race of the week on the K2 Trooper Triumph by Smiths Racing.
Having finished third in the first Supersport race earlier in the week, he went two places better, leading the race on both laps to claim his first-ever TT victory in the class.
“I was trying so hard to win the race on the little Triumph,” he said.
“We had a lot of input from Triumph this year and it has made all the difference.
“The bike was absolutely mega and I am so happy for the Smiths Racing team; they have done a cracking job on the K2 Trooper Triumph.
“That was only my sixth lap on the bike this week, two laps in practice, two in the first race and two today.”
Next up was the Superstock race run over three laps.
Having won the race last year, Hickman was odds-on favourite for this year and he didn’t disappoint, leading the race from start to finish to win by 26 seconds from Dean Harrison.
This brought his career total of TT wins to five, and completed his treble.
“I don‘t know what it is about this class, the last couple of years I have been so strong,” Hickman added.
“The Smiths Racing team has given me such a good bike and BMW make such a fantastic S1000RR machine and the rest is history.
“I just get on and ride it and for whatever reason it all just clicks.”
Later that evening Hickman went out on the new Norton Superlight in the Lightweight class and brought it home in eighth place.
Hickman said: “I was excited to be riding a British Lightweight bike at the TT.
“The ride also means a lot to me because of my dad’s history with the Norton.”
Hickman’s father Dave, formally a GP racer, played an important role in the development of the Rotary Norton in the 1980s and 1990s so it seemed fitting his son should race the new Norton Superlight at the TT.
The big race of TT week, the Senior TT, followed on Friday with Hickman defending his title.
The Lincolnshire rider set the fastest-ever lap of 135.452mph in doing so which gave him the title of the fastest road racer of all time.
As favourite to win again, he led the first four of the six 37.7-mile laps by 17.4 seconds, but then encountered a bike problem.
He nursed it over the final two laps, but was down on power and ended up second to Harrison.
Hickman returns to domestic racing in the British Superbikes this weekend at Brands Hatch.
Timetable: Friday – free practice 10.15am, 3.15pm; Saturday – free practice 10.15am, qualifying 4pm; Sunday – warm-up 9.25am, race one (20 laps) 1.30pm, race two (20 laps) 4.30pm.