Army Staff Sgt. Michael Ollis died shielding a fellow soldier from a suicide bomber, but the Staten Island hero’s legacy is still very much alive. It’ll live on at Sunday’s New York City Marathon through the sisters he left behind, and Lt. Karol Cierpica, the Polish soldier he sacrificed his life to save.

Two years after Ollis’ sacrifice in Afghanistan, Cierpica has formed a bond with the Ollis family. It will get stronger every step of their 26.2-mile trek, as he flew into New York to run alongside Ollis’ sisters, Kelly Manzolillo and Kimberly Loschiavo. The sisters previously ran the race in 2008. Now they’ve got added a third member to their team, one with a unique bond.

“I feel lucky, because other families who have lost a loved one don’t have a connection like this,’’ said Manzolillo, who lives in Hawaii. “We have someone who was there with Michael, the closest thing we can relate to.’’

It’s an unlikely connection.

Ollis was serving with the 2nd Battalion, 22nd Infantry Regiment, 1st Brigade Combat Team, 10th Mountain Division (Light) out of Fort Drum. His platoon was held over to do extra work, and at 3:54 a.m. on Aug. 28, 2013, a car bomb blasted a hole in the wall of FOB Ghazni. Al-Qaeda rebels fired mortar shells, shoulder-fired rockets and hand grenades into the base, and 10 suicide bombers breached the post.

Ollis and Cierpica — fighting side-by-side according to Cierpica — and a team of Special Forces troops killed eight, and a ninth was shot. But when the last sprung out from behind some containers, Ollis stepped forward to protect Cierpica. The bomber detonated his vest and killed Ollis, 24, who received a posthumous Silver Star for his heroism.

Ollis received Poland’s highest honor for a foreign soldier, the Army Gold Medal. His parents, Bob and Linda, and sisters were flown to Poland for two weeks in August 2014, received by Poland’s President Komorowski, Prime Minister Donald Tusk and the U.S. ambassador.

But their most emotional meeting was with Cierpica and his pregnant wife Basha.

“He absolutely looked scared, like a deer in headlights when he was staring at us,” Bob said. “I grabbed him and I hugged him. That’s when the tension broke.’’

“It was very emotional for me because of meeting the family,” Cierpica said. “I remember exactly where I was. It was very emotional when I met Ollis family.’’

“We had a lot of questions for him when we met at the consulate,’’ said Loschiavo, who lives in Spotswood, N.J. “He was the last person to see my brother, to communicate with [him]. I wanted to know exactly what happened. We’d heard [little] from the government; we just knew very basically from the Associated Press. That’s all we had, and whatever Michael’s friends had put together.

“I don’t think in a situation like this you ever get closure. We were like the second and third mothers. He was our baby, there was so big an age difference. … He made a choice to save other people, especially Karol. He brought [Karol] to us to help us remember our brother. It’s a way to never forget what he was about. We have a living legacy … and that’s amazing.’’

The Ollis family sent the Cierpicas a teddy bear Manzolillo had made from Michael’s Army fatigues. And when the Cierpica’s baby was born Jan. 11, they named him Michael. The families’ rapport grew, until Cierpica reached out to Manzolillo about running the marathon in Ollis’ memory.

“I was very surprised. We were so pleased. We’re just thrilled about it,’’ Linda said.

“My sister and I are members of the New York Road Runners Club. It was natural. I wouldn’t say we’re avid runners, but we run for fun,’’ said Manzolillo, who will be running for the Staff Sgt. Ollis Freedom Foundation.

“I’m a soldier, [but] actually, running is my passion. … What is important for me is the marathon we run together with my friends to honor [Ollis],’’ said Cierpica, who started the Thank You For Your Service foundation . “My mission is for servicemen like Michael, servicemen and family who lost fathers, sons, fighting for their country.’’

The New Dorp street where Ollis grew up bears his name, as does the field at the Michael J. Petrides School he attended. There’s a monument planned in his honor, but there may be no more moving honor than Sunday’s race.