Von Hoff has WorldTour experience having raced with the Garmin team for three years before dropping down two tiers this season with British Continental outfit NFTO, where he has been competing against some of his future teammates.
"After racing against ONE Pro Cycling all year I have seen how professional the team has been managed and raced with a strong team environment," said the 27-year-old in a statement from the British team.
Von Hoff has had a successful season, winning the Australian Criterium Championships in January before taking a stage of the Tour Down Under in national colours. He has also taken victories on British roads for ONE Pro at the Rutland-Melton CiCLE Classic and at the Canary Wharf round of the Tour Series.
"My goal this year has been to step back to racing in the top tier so I can show what I can do and with ONE Pro Cycling progressing from the British domestic scene to Pro-Continental it felt like a natural fit," he added.
"Here they will get invited to some of the biggest races in the World and I'll be able to race back at the top level. I believe that with the right support I can beat some of the fastest guys in the world."
ONE Pro, which was formed in February this year by former cricketer Matt Prior, have submitted an application to move up to the Pro Conti ranks for 2016. Should they be successful, they'd need to expand their roster to a minimum of 14 riders, a figure that has now been surpassed as Von Hoff follows a string of new signings.
As well as retaining a core of eight current riders – including Marcin Bialoblocki, winner of a stage at the WorldTour Tour de Pologne and ninth in the World Championships time trial – the team has made seven new signings now. Similarly to Von Hoff, the team has acquired the services of former Danish road race champion Sebastian Lander, another rider who has WorldTour experience (with BMC) and has spend this year at Continental level (with TreFlor-Blue Water).
Karol Domagalski, who used to ride for Caja Rural and has ridden the Vuelta a Espana, has joined from Raleigh, while former British road race champion Kristian House signed after eight seasons with the currently-named JLT-Condor team. On top of that, the team has invested in youth, signing Dion Smith, James Oram and Hayden McCormick, who were all part of New Zealand's U23 squad at the recent World Championships in Richmond.
"Having announced some very exciting names to join ONE Pro Cycling for the 2016 season this is another that shows our intentions for next year," said Prior.
"Steele is a fantastic rider who has experienced success at the top level. He is hugely motivated to get back to the top, racing and winning against the best in the world. He will bring a huge amount of motivation but also a level of competitiveness that will be very healthy for our group."