Beckham arrived Monday wearing a bright colored sweatsuit jacket and hat. The New York Giants traded Beckham to the Browns last month. He attended the voluntary off-season program while with the Giants last year.
Browns wide receiver Jarvis Landry also attended the first day of the program, which included an open training room and weight room, meetings, breakfast and lunch.
Beckham will join Browns coach Freddie Kitchens, quarterback Baker Mayfield and Landry at a news conference at 1:30 p.m.
The Browns have rookie minicamp May 3 and OTA sessions No. 2 on May 15.
Beckham is set to make $16.7 million in base salary this season. The three-time Pro Bowl selection had 77 catches for 1,052 yards and six scores in 12 starts in 2018. Beckham went down a quad injury in Week 12 and missed the final four games of the season.
Cleveland was one of several teams allowed to begin its off-season workout program early because the team hired a new coach. The Miami Dolphins and Tampa Bay Buccaneers also began their programs Monday. The Denver Broncos begin their off-season program Tuesday.