Dennis Duncan, Business Attorney in Sioux Falls, South Dakota
Over 53 years of legal practice · focused on Business, Formation, and Government · 5.0/5 rating from 1 verified client review
MemberatThe Duncan Law Firm LLP
Sioux Falls, SD
Practicing business in Sioux Falls since 1973.
- 53+
- Years practicing
- 5.0 ★
- 1 client review
- 2
- Bar admissions
Are you Dennis Duncan?
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Quick answer
Dennis Duncan is a member based in Sioux Falls, SD. The practice focuses on Business, Formation, and Government. Dennis has over 53 years of legal experience. Currently practicing at The Duncan Law Firm LLP. Rated 5.0 out of 5 from 1 client review.
- Based in
- Sioux Falls, SD
- Experience
- over 53 years
- Known for
- Business · Formation · Government
- Handles Business, Formation, and Government matters from Sioux Falls, SD.
- Over 53 years of practice as a licensed attorney.
- Recognized with AV Preeminent.
About Dennis Duncan: Dennis Duncan is a member based in Sioux Falls, SD. The practice focuses on Business, Formation, and Government. Dennis has over 53 years of legal experience. Currently practicing at The Duncan Law Firm LLP. Rated 5.0 out of 5 from 1 client review.
Areas of practice
Dennis's practice areas in Sioux Falls
Dennis concentrates on business, formation, government, health care, and insurance. Each area below outlines the kind of case Dennis handles, typical outcomes to expect, and how the intake process starts.
Business
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Formation
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Government
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Health Care
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Insurance
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Litigation
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Business cases in Sioux Falls, South Dakota
Dennis takes business matters in Sioux Falls, South Dakota. Typical engagements include intake calls to scope the issue, review of any records or filings you already have, and a written strategy memo before Dennis agrees to represent you.
Formation cases in Sioux Falls, South Dakota
Dennis takes formation matters in Sioux Falls, South Dakota. Typical engagements include intake calls to scope the issue, review of any records or filings you already have, and a written strategy memo before Dennis agrees to represent you.
Government cases in Sioux Falls, South Dakota
Dennis takes government matters in Sioux Falls, South Dakota. Typical engagements include intake calls to scope the issue, review of any records or filings you already have, and a written strategy memo before Dennis agrees to represent you.
Health Care cases in Sioux Falls, South Dakota
Dennis takes health care matters in Sioux Falls, South Dakota. Typical engagements include intake calls to scope the issue, review of any records or filings you already have, and a written strategy memo before Dennis agrees to represent you.
Insurance cases in Sioux Falls, South Dakota
Dennis takes insurance matters in Sioux Falls, South Dakota. Typical engagements include intake calls to scope the issue, review of any records or filings you already have, and a written strategy memo before Dennis agrees to represent you.
Biography
Dennis Duncan, business attorney serving Sioux Falls
Dennis Duncan is a member based in Sioux Falls, SD. The practice focuses on Business, Formation, and Government. Dennis has over 53 years of legal experience. Currently practicing at The Duncan Law Firm LLP. Rated 5.0 out of 5 from 1 client review. Dennis works from Sioux Falls, South Dakota and takes on business matters across the region.
Dennis Duncan is a lawyer practicing legislative lobbying, civil litigation, insurance and 4 other areas of law. Dennis received a B.A. degree from University of South Dakota in 1970, and has been licensed for 53 years. Dennis practices at The Duncan Law Firm LLP in Sioux Falls, SD and 1 other location.
How Dennis handles business matters
Dennis Duncan is a lawyer practicing legislative lobbying, civil litigation, insurance and 4 other areas of law. Dennis received a B.A. degree from University of South Dakota in 1970, and has been licensed for 53 years. Dennis practices at The Duncan Law Firm LLP in Sioux Falls, SD and 1 other location.
Who Dennis represents
Dennis reviews new inquiries case-by-case for business, formation, and government matters in Sioux Falls and the surrounding South Dakota area.
Credentials
Credentials — where Dennis studied and practices
University of South Dakota
J.D. · 1973
University of South Dakota
B.A. · 1970
Jurisdictions
Dennis's state bar admissions
U.S. District Court,
1974 · ACTIVE
South Dakota
1973 · ACTIVE
Dennis studied at J.D. in University of South Dakota and B.A. in University of South Dakota.
Law school and academic background
Dennis completed J.D. in University of South Dakota and B.A. in University of South Dakota. Formal legal training is one signal of substantive knowledge — the day-to-day practice Dennis runs in South Dakota is where that training gets applied to real client questions.
Recognition
Dennis's legal honors and published work
Dennis has received 1 formal recognition from bar associations, industry bodies, and peer-review services.
AV Preeminent
Legal awards and honors
AV Preeminent.
Affiliations
Dennis's professional memberships and bar associations
The State Bar of South Dakota American Bar Association South Dakota Defense Lawyers Association American Medical Association
Member, Physician Advisory Network, 1994— · membership
Locations
Dennis Duncan's office in Sioux Falls
Dennis's primary office is at 515 W. Landscape Pl., Ste. 101, Sioux Falls, SD, 57108. In-person meetings are by appointment; a phone intake usually comes first.
The Duncan Law Firm LLP
515 W. Landscape Pl., Ste. 101
Sioux Falls, SD 57108
Open in Google MapsClient feedback
Client reviews of Dennis Duncan — 5.0/5 rating from 1 verified client review
Every review below is from a verified client of Dennis. Reviews cover communication, case outcome, and value — the three signals that matter most when comparing business attorneys in Sioux Falls.
5.0
1 client review
Client ratings are sourced from public records and editorial research. Reviews on LawyersListed are accepted from verified clients once Dennis Duncan claims this profile.
Read all reviewsHiring guide
How to hire Dennis Duncan — what to expect in your first consultation
Working with a new business attorney should feel structured. Here's how the first two conversations with Dennis usually go, from the moment you request a consult to the day representation begins.
Consultation formats and pricing
Dennis charges for the initial consult. That fee is credited toward representation if you retain Dennis's office.
What to bring to your first meeting
Bring any documents you already have — police reports, medical records, filed pleadings, correspondence from an insurer, a copy of the contract at issue. If you're not sure, err on the side of bringing everything; Dennis will tell you what matters and what doesn't.
Questions to ask a business attorney in Sioux Falls, South Dakota
A short list to run through before you commit: How many business matters have you handled in the last year? What's your fee structure? Who else in the office will work on this? What's your realistic estimate of timeline and range of outcomes? How do I reach you between meetings?
Fees & payment
Fees, payment methods, and consultation options for Dennis
Dennis discusses fees during intake so the arrangement fits the matter. Contingency, hourly, and flat-fee options are all common in business practice — ask which fits.
Hourly rates, contingency fees, and flat-fee options
Every business matter is priced differently. Simple document review might be a flat fee. Injury litigation is often contingency. Complex commercial disputes usually run hourly with a retainer. Dennis confirms the model in the engagement letter before any work starts.
Payment methods and payment plans
Dennis's office accepts standard payment methods. Ask about payment plans if the retainer is a stretch — many business practices work with clients on structured schedules.
Frequently asked
Frequently asked questions about Dennis Duncan
How much does it cost to hire Dennis for a business case?
Cost depends on the type of matter, the fee model (contingency, flat, hourly), and how contested the case becomes. Dennis walks through the likely range during the consult so there are no surprises.
Does Dennis offer a free consultation?
Dennis charges for the initial consult; that fee is credited toward representation if you retain Dennis's office. Some business attorneys offer free consults — check Dennis's current terms during booking.
How long do business cases in South Dakota typically take?
Simple business matters can wrap in a few weeks; disputed cases can run 6–18 months from intake to resolution, longer if the matter goes to trial. Dennis gives a realistic estimate for your facts at the consult — vague answers here are a red flag.
Can Dennis take my case if I'm outside Sioux Falls?
Dennis is licensed in South Dakota. Matters governed by South Dakota law are the natural fit. Out-of-state matters are handled case-by-case, sometimes with local co-counsel. Ask during intake — Dennis will tell you if the case is a fit or refer you to someone closer to your court.
What should I bring to my first meeting with Dennis?
Bring every document that touches the dispute: contracts, correspondence, police or medical reports, filed pleadings, invoices, photographs, insurance letters. Also bring a written timeline of what happened, in your own words. Dennis will filter what matters — over-preparing at intake is always cheaper than needing a second meeting.
Is Dennis accepting new business clients right now?
Dennis's intake status shifts week to week. Submit the form; the office will confirm availability or refer the matter out.
Areas served
Business attorneys serving Sioux Falls, Rapid City and Pierre in South Dakota
Dennis handles business matters throughout South Dakota. Each city below is a direct link into the search page for verified business attorneys in that community.
More counsel
Other top-rated business attorneys in South Dakota
If Dennis's intake is full or the fit isn't right, these business attorneys in Sioux Falls handle similar matters. Every profile below is verified and open to consultations.





