The 36-year-old is defending champion over 5,000m and 10,000m – although he will just target the longer distance at next summer’s Games.
"Tokyo 2020, I’m going to be back on the track," he said. "I’m really excited to be competing back on the track and give it a go in the 10,000m.
"Hopefully I haven’t lost my speed. I’ll train hard for it and see what I can do."
Farah switched to the marathon after the IAAF World Championships in London two years ago but struggled to match his exploits on the track.
Although he won the Chicago Marathon in 2018, setting a European record of 2:05:11, he faced a monumental challenge to close the gap on the world’s best.
Kenya’s Eliud Kipchoge recently broke the two-hour barrier in the Ineos 1:59 Challenge in Vienna, while Ethiopian legend Kenenisa Bekele is over three minutes quicker than Farah over 26.2 miles.
"It's been really exciting competing in the marathon over the last couple of years," added Farah.
"To win the Chicago Marathon was nice and to finish third in the London Marathon was ok, and it's been a great learning curve for me."
Farah won gold over 5,000m and 10,000m at London 2012 and Rio 2016, while he is also a six-time world champion.