McKittrick was born in Drumaness, County Down on 8 December 1860, the fourth child of Eliza Black and Edward Amlave McKittrick, Principal of Drumaness High School. She was christened Anna Margaret at Third Ballynahinch Presbyterian Church on 27 January 1861. In the 1880s she attended Marlborough Teacher Training College in Dublin, was appointed Monitor at Millbrook National School, Larne, County Antrim, finished her training at Marlborough and then became a qualified teacher at the same school.

It was during her first visit to Larne that she met Andrew Ross, a widower of 35, who was station master there. She married him at Joymount Presbyterian Church, Carrickfergus, County Antrim on 30 August 1887. She died after a fall in her home in 1939.

She wrote under the pen-name Amanda McKittrick Ros, possibly in an attempt to suggest a connection to the noble de Ros family of County Down. Ros was strongly influenced by the novelist Marie Corelli. She wrote: "My chief object of writing is and always has been, to write if possible in a strain all my own. This I find is why my writings are so much sought after."Her admirers included Mark Twain, Lord Beveridge, and Aldous Huxley. Her novel Irene Iddesleigh was published in 1897. It was reviewed by humorist Barry Pain who sarcastically termed it "the book of the century." Ros retorted in her preface to Delina Delaney by branding Pain a "clay crab of corruption," and suggesting that he was so hostile only because he was secretly in love with her. But Ros claimed to have made enough money from her second novel, Delina Delaney, to build a house, which she named Iddesleigh.

Belfast Public Libraries has a large collection of manuscripts, typescripts and first editions of her work. Manuscript copies include Irene Iddesleigh, Sir Benjamin Bunn and Six Months in Hell. Typescript versions of all the above are held together with Rector Rose, St. Scandal Bags and The Murdered Heiress among others. The collection of first editions covers all her major works including volumes of her poetry Fumes of Formation and Poems of Puncture, together with lesser known pieces such as Kaiser Bill and Donald Dudley: The Bastard Critic. The collection includes hundreds of letters addressed to Ros, many with her own comments in the margins. Also included are typed copies of her letters to newspapers, correspondence with her admiring publisher T.S. Mercer, an album of newspaper cuttings and photographs, and a script for a BBC broadcast from July 1943.

Nick Page, author of In Search of the World's Worst Writers, rated Ros the worst of the worst. He says that "For Amanda, eyes are 'piercing orbs', legs are 'bony supports', people do not blush, they are 'touched by the hot hand of bewilderment.'"

Her novels

Aldous Huxley wrote that "In Mrs. Ros we see, as we see in the Elizabethan novelists, the result of the discovery of art by an unsophisticated mind and of its first conscious attempt to produce the artistic. It is remarkable how late in the history of every literature simplicity is invented." This is how she informs the reader how Delina earned money by doing needlework:

She tried hard to keep herself a stranger to her poor old father's slight income by the use of the finest production of steel, whose blunt edge eyed the reely covering with marked greed, and offered its sharp dart to faultless fabrics of flaxen fineness.

Her novel Delina Delaney begins:

Have you ever visited that portion of Erin's plot that offers its sympathetic soil for the minute survey and scrutinous examination of those in political power, whose decision has wisely been the means before now of converting the stern and prejudiced, and reaching the hand of slight aid to share its strength in augmenting its agricultural richness?

Page comments: "I first read this sentence nearly three years ago. Since then, I have read it once a week in an increasingly desperate search for meaning. But I still don't understand it." (The sentence approximately means, "Have you ever been to that part of Ireland which has been studied by the government, who have aimed to modernise its agriculture?")

The Oxford literary group the Inklings, which included such luminaries as C. S. Lewis and J. R. R. Tolkien, held competitions to see who could read Ros' work for the longest length of time while keeping a straight face.

Northrop Frye said of Ros's novels that they use "rhetorical material without being able to absorb or assimilate it: the result is pathological, a kind of literary diabetes".

Her poetry

A poet as well as a novelist, Ros wrote Poems of Puncture and Fumes of Formation. The latter contains "Visiting Westminster Abbey," which opens:

Holy Moses! Have a look!

Flesh decayed in every nook!

Some rare bits of brain lie here,

Mortal loads of beef and beer,

Some of whom are turned to dust,

Every one bids lost to lust;

Royal flesh so tinged with 'blue'

Undergoes the same as you.

As of 2004, none of her works are in print. Her books are rare and first editions command prices of $300 to $800 in the used-book market. Belfast Central Library has an archive of her papers, and the Queen's University of Belfast has some volumes by Ros in the stacks.

The Frank Ferguson-edited collection, Ulster-Scots Writing: An Anthology (Four Courts, 2008) includes her poem, 'The Town of Tare'.

On 11 November 2006 as part of a 50 Year celebration, renowned librarian Elspeth Legg hosted a major retrospective of her works, culminating in a public reading by 65 delegates of the entire contents of 'Fumes of Formation'. The theme of the workshop that followed was 'Suppose you chance to write a book', Line 17 of 'Myself' from page 2 of Fumes of Formation.

• Irene Iddesleigh (novel, 1897)
• Delina Delaney (novel, 1898)
• Poems of Puncture (poetry, 1912)
• Fumes of Formation (poetry, 1933)
• Helen Huddleston (posthumous novel)

• Jack Loudan (1954) O Rare Amanda!: The Life of Amanda McKittrick Ros (London: Chatto & Windus 1954)
• Thine in Storm and Calm - An Amanda McKittrick Ros Reader, edited by Frank Ormsby (The Blackstaff Press, 1988.)