I tried hard to make Linear Algebra Done Right error-free, but spotting mistakes in one's own writing can be difficult in a book-length work. All errors in the third edition that I know about are listed below. These errors were corrected in the fourth edition.

- page xiii, line 8: “that that” should be “that”.

- page 3, Example 1.4: There is no need to mention λ.

- page 6, third line above 1.10: The word following “replace” should be “the”.

- page 59, first line in second bullet point: “
*L*(**C**^{3},**F**)” should be “*L*(**C**^{3},**C**)”.

- page 72, line 6: “
*T*” should be “*D*”.

- page 85, lines 2, 4, 7, and 9: “
*M*(*v*)” should be “_{k}*M*(*Tv*)”._{k}

- page 98, third line of proof of part (b): “0” should be “{0}”.

- page 114, Exercise 18: Assume that
*U*is a nonempty subset of*V*.

- page 115, last line: The second “
*u*” should be “_{n}*v*”._{n}

- page 123, ten lines from bottom: “its proof” should be “in its proof”.

- page 130, Exercise 11, part (b): Delete “dim”.

- page 138, first line of Solution (b): “
*V*” should be “**F**^{2}”.

- page 151, sixteen lines from bottom: “restricted to dim span(
*v*_{1}, ... ,*v*)” should be “restricted to span(_{j}*v*_{1}, ... ,*v*)”._{j}

- page 153, Exercise 8: “-1” should be “-
*I*”.

- page 153, Exercise 11: “polynomial” should be “nonconstant polynomial”.

- page 156, third line of proof of 5.38: “
*E*(λ,*T*)” should be “*E*(λ_{j},*T*)”.

- page 161, Exercise 15: “
**F**^{3}” should be “**C**^{3}”.

- page 166, line before Example 6.4: “
*w*” should be “*u*”.

- page 168, line 1: “(a)” should be “(b)”.

- page 175, Exercise 5: Assume that
*V*is finite-dimensional.

- page 177, Exercise 17: The right side of the displayed equation should be “max{|
*x*|, |*y*|}”.

- page 177, Exercise 18: The right side of the displayed equation should be “(|
*x*|^{p}+ |*y*|^{p})^{1/p}”.

- page 183, line 4 of Proof: “1 <
*j*<*m*” should be “1 <*j*≤*m*”.

- page 193, first line after 6.45: “line in
**R**^{3}” should be “line in**R**^{3}containing the origin”.

- page 193, second line after 6.45: “plane in
**R**^{3}” should be “plane in**R**^{3}containing the origin”.

- page 229, line 9: “basis” should be “orthonormal basis”.

- page 232, Exercise 11: “on” should be “in”.

- page 239, Exercise 6: The first “
*P*(**R**^{2})” should be “*L*(*P*_{2}(**R**))” and the second “*P*(**R**^{2})” should be “*P*_{2}(**R**)”.

- page 240, Exercise 17, part (d): The phrase “for every
*v*∈*V*” is redundant and should be deleted.

- page 247, displayed equation three lines above 8.15: The second “
*w*” should be “*v*_{1}”.

- page 252, line before 8.20: “is” should be “are”.

- page 268, Exercise 7: “
*T*” should be “*P*”.

- page 273, second line from bottom: “λ
_{m}” should be “λ_{j}”.

- page 277, 11 lines from bottom: “Im
_{n}” should be “Im λ_{n}”.

- page 284, fourth line of proof of 9.23: “8.36(a)” should be “8.36(b)”.

- page 325, line 6 of the proof of 10.52: “λ
_{1}*r*” should be “λ_{1}*r*_{1}” and “λ_{n}*r*” should be “λ_{n}*r*_{n}”.

- page 325, line 7 of the proof of 10.52: “Ω” should be “
*B*”.

- page 326, first line of proof of 10.54: “
*V*” should be “**R**^{n}”

- page 329, line 11: “
*y*=*f*(*x*)” should be “*y*= σ(*x*)”.