A(i)da Mason, née Wagstaff (24 September 1895 – 9 February 2007) was the oldest living person in the UK at 111 years of age, from the death of fellow 111-year-old Scotswoman Annie Knight on 27 November 2006, until Mason's own death at age 111 years, 138 days.
Mason was born in Chesterfield, England, and was schooled until age 13, whereupon she went into service in Bradford with a family who ran an off-licence. She later married John Mason, a miner, in 1914, after which they lived together at Upton, West Yorkshire until John died in 1962. Mason spent time with John at Butlins in Filey and Skegness where she worked making sandwiches. Ada had an aunt who lived to 104.
Mason outlived all five of her children and attributed her long life to eating bread dripping with salt every day, along with clean living. She was confined to her bed for the last couple of years of her life. She was the last living person in the UK born in 1895. Upon her death, then-110-year-old Florrie Baldwin became the oldest living person in the UK.