DBA has several meanings:

• database administrator (or analyst)
• De Bellis Antiquitatis, a tabletop wargame.
• decibels, weighting method "A", measured in dBA or dB(A). See Bel (acoustics).
• Deutsche BA, a low-cost airline.
• Doctor of Business Administration, a terminal degree. See also Doctorate
• doing business as, more often as d/b/a