User:KTC/Fellows of the Royal Society/A
- Charles Abbot, 1st Baron Colchester
- John Farr Abbot
- Louis Paul Abeille
- Clarke Abel
- Sir Frederick Augustus Abel
- Michael Abercrombie
- John Abernethy
- Mohammed Ben Ali Abgali
- Sir William de Wiveleslie Abney
- Sir Edward Penley Abraham
- Samson Abramsky
- Sir Henry Wentworth Dyke Acland
- Sir Thomas Dyke Acland
- Gilbert Smithson Adair
- James Adair
- John Adair
- Robert Alexander Shafto Adair, 1st Baron Waveney
- Neil Kensignton Adam
- Robert Adam
- John George Adami
- Alfred Rodney Adams
- Andrew Leith Adams
- Frank Dawson Adams
- Jerry McKee Adams
- Sir John Bertram Adams
- John Couch Adams
- John Frank Adams
- Paul Richard Adams
- William Grylls Adams
- Michel Adanson
- Cyril Clifford Addison
- William Addison
- Swithin Adee
- Saul Adler
- Edgar Douglas Adrian, 1st Baron Adrian of Cambridge
- Richard Hume Adrian, 2nd Baron Adrian of Cambridge
- Adam Afzelius
- Cassem Algiada Aga
- George Charles Agar
- Welbore Ellis Agar
- Wilfred Eade Agar
- George James Welbore Agar-Ellis, 1st Baron Dover
- William Aglionby
- George Andre Agricola
- Cyriacus Ahlers
- Sir George Biddell Airy
- James Edward Tierney Aitchison
- Alexander Craig Aitken
- John Aitken
- Martin Jim Aitken
- Sir William Aitken
- Michael Edwin Akam
- Mark Akenside
- Sir Wallace Alan Akers
- Muhammad Akhtar
- John Fortescue Aland, 1st Baron Fortescue of Credan
- Giambattista Albertini
- Wyndham John Albery
- Bernard Siegfried Albinus
- Alfred William Alcock
- Nathan Alcock
- Roger William Alder
- Robert Aldersey
- Sir James Alderson
- David John Aldous
- Jean le Rond d'Alembert
- Henry Alexander
- Robert Alexander
- Robert McNeill Alexander
- Francesco Algarotti
- Archibald Alison
- Johann Nicholaus Sebastian Allamand
- Thomas Allan
- Sir Thomas Clifford
- Edgar Johnson Allen
- Edmond Allen
- Sir Geoffrey Allen
- Herbert Stanley Allen
- John Allen
- John Frank Allen
- John Robert Laurence Allen
- Norman Percy Allen
- Percival Allen
- Thomas Allen
- William Allen
- William Allen
- John Alleyne
- Thomas Edward Allibone
- Carlo Allioni
- William Allix
- George James Allman
- George Johnston Allman
- Arthur John Allmand
- Jacques Eugene d'Allonville, Chevalier de Louville
- Theodore de Almeyda
- Johann Wilhelm Alruz
- John Alstroemer
- George John Althorp, 2nd Earl Spencer
- John Charles Althorp, 3rd Earl Spencer
- Joseph Ames
- John Amman
- Emmanuel Ciprian Amoroso
- William Bradshaw Amos
- Claude Amyand
- Thomas Amyot
- John Proctor Anderdon
- Brian David Outram Anderson
- Donald Thomas Anderson
- Ephraim Saul Anderson
- Sir Hugh Kerr Anderson
- Jan Mary Anderson
- John Anderson
- John Anderson
- John Stuart Anderson
- Sir Roy Malcolm Anderson
- Sir William Anderson
- Antonio Freyre de Andrade
- Edward Neville da Costa Andrade
- Edward Raymond Andrew
- James Andrew
- Sydney Percy Smith Andrew
- Christopher Howard Andrewes
- Sir Frederick William Andrewes
- Charles William Andrews
- Joseph Andrews
- Thomas Andrews
- Thomas Andrews
- James Roger Prior Angel
- Thomas Anguish
- Bernt Anker
- Carsten Anker
- Arthur Annesley, 1st Earl of Anglesey
- Arthur Annesley, 1st Earl of Mountnorris
- Francis Annesley
- George Annesley, 2nd Earl of Mountnorris
- James Annesley
- Gleb Anrep
- Charles Ansell
- George Anson, Baron Anson of Soberton
- Thomas Anson
- David Thomas Ansted
- Gebhard d'Anteny
- Janis Antonovics
- Sir Edmund Antrobus
- James Apjohn
- Sir Edward Victor Appleton
- John George Appold
- Francesco d'Aquino, Prince of Caramanico
- Nicolo Alerbo d'Aragona, Prince of Cassano
- Agnes Arber
- John Arbuthnot
- John Arbuthnot
- William Archer
- Charles Dickson Archibald
- Charles George Arden, Baron Arden
- Richard Pepper Arden, Baron Alvanley
- Sir Charles Frederick Arden-Close
- James Arderne
- William Arderon
- Robert Areskine
- Antoine Joseph Degallier d'Argenville
- John Argyris
- William Joscelyn Arkell
- Sir Joseph Arthur Arkwright
- Sir Alexander Armstrong
- Edward Frankland Armstrong
- Henry Edward Armstrong
- John Armstrong
- Robert Young Armstrong
- William George Armstrong, Baron Armstrong of Cragside
- Ulrich Wolfgang Arndt
- James Henry Arnold
- John Oliver Arnold
- James Moncrieff Arnott
- Neil Arnott
- Struther Arnott
- Cyril Arthington
- James Greig Arthur
- Richard Arundel
- Peter Ascanius
- Edward Ash
- Sir Eric Albert Ash
- John Ash
- Michael Ashburner
- Eric Ashby, Baron Ashby of Brandon, Suffolk
- Michael Farries Ashby
- Shukbrugh Ashby
- Frances Mary Ashcroft
- St George Ashe
- William Windham Ashe
- Jonathan Felix Ashmore
- Norman Henry Ashton
- James Hartley Ashworth
- Anthony Askew
- Brigitte Alice Askonas
- Stephanus Evodius Assemanni
- Richard Assheton
- Alan Astbury
- William Thomas Astbury
- Edward Astle
- Thomas Astle
- Francis Aston
- Francis William Aston
- David Francis Atcherley
- Sir Michael Francis Atiyah
- William Ringrose Gelston Atkins
- Colin Atkinson
- Sir Robert Atkyns
- John Attfield
- Clement Richard Attlee, 1st Earl Attlee
- David Ian Attwell
- Joseph Atwell
- George Atwood
- Abraham d'Aubant
- Alexander Aubert
- John James Audubon
- Charlotte Auerbach
- John Auldjo
- Louis d'Aumont de Rochebaron
- James Peter Auriol
- George Aust
- Philip d'Auvergne, Duc de Bouillon
- Adrian Auzout
- Giuseppe Averani
- Sir William Ian Axford
- Sir Joseph Ayloffe
- Charles Nicholas Ayres
- Thomas Ayres
- William Ayrton
- William Edward Ayrton
- Marco Antonio de Azevado Coutinho