Theistic science, also referred to as theistic realism, is the proposal that the central scientific method of requiring testability, known as methodological naturalism, should be replaced by a philosophy of science that allows occasional supernatural explanations which are inherently untestable. Proponents propose supernatural explanations for topics raised by their theology, in particular evolution.

Supporters of theistic realism or theistic science include intelligent design creationism proponents J. P. Moreland, Stephen C. Meyer and Phillip E. Johnson.

Instead of the relationship between religion and science being a dialogue, theistic science seeks to allow exceptions to the basic methods of science, and present miraculous interventions as a scientific explanation when a natural explanation has not been found. As Alvin Plantinga acknowledges, this is a "science stopper", and these concepts lack any mainstream credence.

In 1987 the United States Supreme Court ruled in Edwards v. Aguillard that a Louisiana law requiring that creation science be taught in public school science classes, along with evolution, was unconstitutional because the law was specifically intended to advance a particular religion. Academic UC Berkeley law professor Phillip E. Johnson, a prominent supporter of the law, became convinced that creationists had lost the case because the methodological naturalism used by the scientific community in defining science does not include supernatural processes, and therefore (unfairly, in his opinion) excluded creationism. He concluded that creationists must therefore redefine science to restore the supernatural, and developed the wedge strategy. The intelligent design movement began with the publication of Of Pandas and People in 1989, and Johnson later became its de facto leader.

In his 1995 book Reason in the Balance: The Case Against Naturalism in Science, Law and Education, Johnson labelled his position theistic realism which, in contrast to methodological naturalism, assumed "that the universe and all its creatures were brought into existence for a purpose by God. Theistic realists expect this 'fact' of creation to have empirical, observable consequences that are different from the consequences one would observe if the universe were the product of non rational causes". While "God always has the option of working through regular secondary mechanisms" which were often to be seen, "many important questions—including the origin of genetic information and human consciousness—may not be explicable in terms of unintelligent causes".

In an essay written in 1996, Johnson wrote of the intelligent design movement that "My colleagues and I speak of 'theistic realism' — or sometimes, 'mere creation' — as the defining concept of our movement. This means that we affirm that God is objectively real as Creator, and that the reality of God is tangibly recorded in evidence accessible to science, particularly in biology." Johnson presents theistic realism as a philosophical justification for intelligent design in his book, Reason in the Balance. According to Johnson, true knowledge begins with the acknowledgment of God as creator of the universe, the unifying characteristic of which is that it was created by God. Theistic realism relies on a concept of God which involves the notions that He is real, personal, and acting in the world through mechanistic creationism.^{[page needed]}

The Wedge Document of 1999 states "Design theory promises to reverse the stifling dominance of the materialist world view, and to replace it with a science consonant with Christian and theistic convictions."

Moreland describes theistic science as a research program that is "rooted in the idea that Christians ought to consult all they know or have reason to believe in forming and testing hypotheses, explaining things in science and evaluating the plausibility of various hypotheses, and among the things they should consult are propositions of theology (and philosophy)", and defines its two central propositions as: