MRS, Mrs, or mrs can refer to:

• Magnetic resonance spectroscopy
• Mandibular repositioning splint
• Marginal rate of substitution, in economics
• Maritime Reaction Squadron of the South African Navy
• Marseille Provence Airport, IATA airport code
• Materials Research Society
• Melbourne Rectangular Stadium
• Metabolic risk score
• Minimal recursion semantics
• modified Rankin Scale, to measure disability after stroke
• Monks Risborough railway station, England; National Rail station code MRS
• Movimiento Renovador Sandinista, a political party in Nicaragua, see Sandinista Renovation Movement
• Mrs., an honorific title for married women
• MRS Logística
• MRS suit, breathing apparatus, see Siebe Gorman#Rebreather equipment
• SQL Server Reporting Services, a Microsoft Reporting Services computer technology to create data reports
• MRS agar, a bacterial growth medium for Lactobacilli
• mrs, abbreviation for maravedis (monetary unit or coin)
• M.R.S. (Most Requested Show), Filipino TV show
• (As Mrs) abbreviation for Maresal, the highest rank in the Army of Turkey

Mrs. (American English) or Mrs (British English) (Standard English pronunciation ) is a commonly used English honorific used for women, usually for those who are married and who do not instead use another title (or rank), such as Dr, Professor, Ms., President, Dame, Prime Minister, etc. In most Commonwealth countries, a full stop (period) is not used with the title. In the United States and Canada a period is used (see Abbreviation).