This is just a mere aggregation of conservative philosophers and philosophies. What counts as conservative and philosopher is open to some interpretation obviously.
Plato
Hegel
Xenophon
Aristotle
Aquinas
Augustine
Machiavelli
Hobbes
Locke
Hume
Smith
Nietzsche
Heidegger
Oakeshott
Schmitt
Burke
Strauss
The Reactionary Mind - Corey Robin
The Enigma of Clarence Thomas - Corey Robin
Cicero
Anscombe
Chesterton
Maritain
Hildebrand
Finnis
Ayn Rand
Luther
William F Buckley
Hayek
Popper
Scruton
Heidegger
de Maistre
Macintryre
Wordsworth
Dostoyevsky
Pascal
Chesteron
Bukanin
Thomas Sowell
Federalist Papers
Vivekananda
Confucius
Jiddu Krishnamurthy
Abu Rayhan al-Birun
Nagarjuna
Michael Sandel
Charles Taylor
Christopher Lasch
Robert Nisbet
Theodore Dalyrymple
Karl Polanyi
John Gray
Richard Weaver
Santayana
Stoicism
Arendt
Nozick
Eric Voegelin
van Til
Friedman
Allan Bloom
Collingwood
Sidgwick
Devlin
New Classical Natural Law folks minus Gary Chartier