Bell, who started five games last year in Philadelphia, would have to pass a physical before the deal becomes official.
He signed a five-year deal with the Eagles last year worth nearly $35 million but was released in February in a salary-cap move. The Cowboys had been in contact with Bell's agent as they worked through Doug Free's pay cut earlier in the spring and finally came to an agreement.
Bell, 6-foot-5 and 311 pounds, gives the Cowboys a veteran option as a backup at either tackle spot. He started 35 of the 40 games he played for Buffalo and Philadelphia. Free, who will earn $3.5 million this year, and Jermey Parnell will compete for Dallas' starting right tackle spot opposite Tyron Smith.
The Cowboys also could parlay one of their veterans into a trade opportunity depending on how things play out toward the end of camp.
The Cowboys also plan to sign quarterback Alex Tanney and wide receiver Lavasier Tuinei, who worked out for the team Tuesday, once they get settled in Oxnard. Tanney signed with Kansas City as an undrafted free agent out of Monmouth (Ill.) College but was cut in May. Tuinei spent time last year in Seattle and was cut by Cincinnati earlier this spring.
If those players pass their physicals, the Cowboys would have one roster spot remaining from Josh Brent's retirement on Thursday.