"The team sprint trio have raced together since 2010 and for the last three years they have been the fastest team in the world," high performance boss Mark Elliott said.
"They have a unique relationship as friends but also individuals who gel together to form an outstanding combination under the direction of coach Anthony Peden.
"This announcement means they can now get on with their preparations for Rio to further enhance their performance as a team.
"(Sam's) dedication and professionalism has been outstanding and he is a real driver for this group."
Hansen will be going to her second Olympics after a sharp rise in international rankings over the last 12 months.
Hansen, 26, took a break from the sport after her London Olympic debut but returned fulltime last year where she has improved rapidly under Peden.
She was sixth fastest in qualifying in the individual sprint and finished fifth overall at the recent world championships.
"Natasha has dedicated herself after returning to the sport and is now achieving the level of international performance that we always knew she was capable of," Elliott added.
The collective New Zealand team have produced strong international form to be, for the first time, one of only three teams to secure a full quota of spots for Rio, alongside Australia and Germany.
There is scope for one more men's rider to be added with individual events, and another women's rider to form a team sprint duo.
Christchurch's Olivia Podmore finished 10th at the worlds in March alongside Hansen in the women's team event.
Invercargill's Matt Archibald was sixth in the kilo time trial at the worlds, finishing .737s off bronze. He will be a leading contender for an extra spot, as will Simon van Velthooven.
Together with the three sprinters confirmed today, have formed the core men's sprint group in the last few years.
"We will only consider nominating further sprint riders subject to performance in training, competition and allocation of final team numbers over this next phase," Elliott said.
Today's was the first of several cycling announcements coming up with Rio selections across the two-wheeled disciplines.
The mountain bike team is due to be named in the first week of June, with the BMX riders announced the following week.
The road riders are expected to be named in later in June with the second batch of track riders, notably the endurance athletes, coming up in the first week of July.
Today's naming brings to 52 New Zealand's Olympic team, with the four riders joining athletes in rowing, sailing, taekwondo, triathlon and canoe sprint already confirmed.
