The nomination of Ramos will go to the Board of Supervisors to approval.
He would fill the spot left vacant when Cameron Beach unexpectedly passed away last month.
Ramos is a community planner at TransForm, a public transportation advocacy group, and a member of the San Francisco Planning and Urban Research Association, according to the mayor's office.
He is a lifelong transit rider who obtained bachelor's degree in geography with an emphasis in city planning from San Francisco State University.
"As a regular transit rider and a daily bicyclist, Joel Ramos will bring valuable experience to the SFMTA board as he is passionate about all modes of transportation, is a team builder that works with the community, and is focused on a transit-oriented city," Lee said in a statement.