What Is Ibid?
Ibid — Latin ibidem, in the same place — is a footnote shorthand meaning the note cites the same source as the note immediately before it. Chicago 17 still permits it but now prefers shortened citations, so whether you use it depends on your instructor and department custom. This page unpacks the definition, the mistakes graders see most, and a worked example you can pattern-match against your own draft.
James Parker, MLS
Citation & Formatting Reviewer · Master of Library Science; 9 years as a reference librarian coaching APA, MLA and Chicago styles
Quick answer
Ibid — Latin ibidem, in the same place — is a footnote shorthand meaning the note cites the same source as the note immediately before it. Chicago 17 still permits it but now prefers shortened citations, so whether you use it depends on your instructor and department custom.
On this page · 4 sections
The definition, precisely
Ibid is the abbreviation of ibidem, Latin for in the same place, and it does one thing in note-based citation: repeats the source of the note directly above. A bare Ibid. means the same page again; Ibid., 44 means the same work, page 44. It only ever looks one note back — if anything inserts a new note between, ibid no longer points where you meant, which is why edits that add footnotes silently break every ibid after them. History departments still teach it; most other fields never touch it.
Chicago 17 marks a shift: the manual still allows ibid but prefers the shortened citation — author's last name, two-to-four-word title, page — because ibid is fragile. Any reordering of notes during revision leaves ibids pointing at the wrong source, and readers of digital papers jump around rather than reading sequentially, so a self-contained shortened note serves them better. The upshot for students: learn both forms, because you will read papers full of ibid in older scholarship and write papers whose instructors want one or the other.
The mechanics are small but graded. Capitalize when the note opens: Ibid., 92. Do not italicize — Chicago treats it as an anglicized Latin word, like versus, not a foreignism. Never use ibid in APA or MLA; they are parenthetical systems with no notes to abbreviate. And never chain ibid to a source that was not the immediately previous note — the single most common ibid error in marked-up drafts, usually born from deleting an earlier note during cleanup. When unsure, the shortened citation form is never wrong under Chicago 17.
The four mistakes graders see most
Every one of these shows up in a stack of sixty papers — usually more than once. Each pairs the error with the fix, so the table doubles as a pre-submission check.
| Common mistake | The fix |
|---|---|
| Using ibid when the previous note cites a different source. | Ibid only points one note back. After any insert or deletion, recheck every ibid in the chain — or use shortened citations and skip the problem. |
| Italicizing Ibid. as if it were a foreign title. | Chicago prints it in plain type, capitalized only when it opens the note: Ibid., 92. |
| Using ibid in APA or MLA papers. | Both are parenthetical styles with no footnotes to shorten. Ibid exists only in note systems like Chicago. |
| Assuming a bare Ibid. lets you cite a new page. | Bare Ibid. means the same work and the same page. A new page needs Ibid., followed by the number. |
A worked example
Three consecutive footnotes in a history paper: note 7 gives the full form for Daniel Turner, The Frontier in American History (New York: Holt, 1920), 58. Note 8 reads Ibid., 112 — same book, page 112. Note 9 reads Ibid., 115. Then note 10 cites a different historian, so note 11, returning to Turner, cannot use ibid; it shortens to Turner, The Frontier in American History, 118. Insert one new note anywhere in that chain and every ibid below it must be rechecked.
Pattern-match your own draft against this example rather than against the definition: concrete cases transfer better than abstract rules, and the example shows what the rule looks like when it is done right.
How ibid differs from its neighbors
Ibid is not idem, which points to the same author of a different work — a distinction even historians rarely need in undergraduate papers. It is not op. cit. or loc. cit., Latin shorthands for earlier-cited works that Chicago abandoned decades ago; if you meet them in old scholarship, they mean the shortened citation that Chicago 17 now writes out. And it is not a substitute for the bibliography: ibid compresses notes only, and the full entry still appears once, alphabetized, at the end of the paper.
Boundary confusion is where most grading deductions live: the term is understood roughly but applied against the wrong neighbor. Pin the boundary above and the term stops being fuzzy in practice, which is what the rubric is actually testing.
What's your next step?
Two taps to the exact page that unblocks this paper.
The 30-second check
Skim the four mistakes above against your draft. Any hit is a fix you can make in minutes — and the format row of the rubric is where they all live.
Questions with exact numbers
Forty-plus student questions — word counts, source math, citation edge cases — answered with the real arithmetic.
Browse the Q&ARelated term: DOI — the neighbor this term is most often confused with. Reading the pair together is how the boundary sticks.
Frequently asked questions
4 answered1Is ibid still used in Chicago style?
Yes, but it is demoted. The 17th edition allows ibid while recommending the shortened citation instead — last name, short title, page — because shortened notes survive reordering. Follow your instructor: history departments vary, and some still grade expecting ibid chains. Either choice is defensible; consistency is not optional.
2How do I cite the same source twice in a row?
In a note system: full form the first time, then Ibid. if the page repeats, or Ibid. plus a new page number. Under modern Chicago practice, the shortened form — last name, short title, page — does the same job and is the safer habit.
3Do I italicize or capitalize ibid?
No italics — Chicago treats it as an anglicized Latinism like versus. Capitalize when the note begins: Ibid., 92. Mid-note it stays lowercase, though it almost always opens a note, since it describes the previous one. Both rules hold in the 17th edition.
4What does Ibid., 44 mean exactly?
The same source as the note immediately above, page 44 instead of the page cited there. The comma plus number is what points to a new page; without it, ibid claims the very same page again, which readers will check and flag if wrong.
James Parker, MLS
Citation & Formatting Reviewer · Master of Library Science; 9 years as a reference librarian coaching APA, MLA and Chicago styles