The first overall pick will be present and accounted for when the Cleveland Browns open training camp on Thursday.
Mayfield is the eighth of the nine Browns draft picks to sign. Remaining is cornerback Denzel Ward, taken fourth overall. The team is hopeful Ward will be signed by the time camp opens on Thursday.
The Browns plan to give Mayfield time to learn. Tyrod Taylor was acquired via trade from Buffalo in the offseason, and Browns coach Hue Jackson has made it clear he will be the starting quarterback.
The team's intention remains to keep Taylor as the starter. Jackson, though, has also said if Mayfield emerges and seizes the job, the team will not hold him back.
"He has a long way to go," offensive coordinator Todd Haley said of Mayfield after minicamp in June. "I'd say it's clear that Tyrod is the leader of this team. That is a big component of that position, also.
"Anytime that you're a young player coming into this league, especially a quarterback, it's going to take time. You have a lot of different things that you're dealing with at that position. For him, a guy that has been in the [shot]gun 99 percent of the time, in this division you have to be under center some."
Haley added: "Whether it's running or play-action, those are some of the things that he has really had to work hard at. But I'm happy that we have training camp because young quarterbacks need all of the time they can get."
Mayfield was a surprise choice with the first selection, but GM John Dorsey and Jackson cited Mayfield's work ethic and competitiveness. Mayfield won the Heisman Trophy as a senior. He started 39 of 40 games at Oklahoma, and left college ranked second in FBS history in passing efficiency rating (175.4), third in yards per attempt (9.7) and tied for fourth in touchdown passes (131).