Leendert "Leonard" Gansevoort (July 14, 1751 – August 26, 1810) was an American political leader from New York who served as a delegate to the Continental Congress in 1788.

[5][6] His father was the third of his family's generation in America, who were prominent brewers and merchants in Albany.

[8][9] After the outbreak of the Revolutionary War, he became a member of the Albany Committee of Correspondence serving as treasurer until November 1775.

[10] He wrote to his brother, Peter on October 31, 1775, stating:[4] "Dr BrotherI can hardly express my Distress upon receiving a Letter from Mr James Van Rensselaer acquainting me with your indisposition and that you in consequence thereof had been obliged to leave Chanblee and that you was then in Coll: Biddels Camp on the North side of St John's; every thing seem'd to consire to confirm me in the Opinion that you must have been very ill you cannot be ignorant of the Emotions in my Breast when you consider that Fraternal Affection which has always subsisted between us, and in what Manner I must have also felt when prompted by Duty I communicated the Contents of the Letter to our Joint Parents, I was oblig'd to meliorate the News by telling them that your indisposition was the Fever Ague but do assure you that upon reading the Letter from the same Gent.

to Mr Philip Van Rensselaer that tho' you was then yet pretty Weak you was greatly recovered, I seem'd to be rais'd from the lowest Abyss of dispondence to the highest pinnacle of Hope and I will leave you to reflect how industrious I was to communicate it to the old people - I beg Dear Brother as you Love your Friends who are under the greatest uneasiness yet that you will write us a Line if you are able, and if not procure some one to write for you - and beg further that if you are not recovered on receipt of this that you will apply for leave to come down and write me before you set out that I may meet you on your Way - I should have been up with you already If I could possibly have obtained leave of HettyWe are well I am Your loving BrotherLeonard GansevoortAlbany Octr 31 1774To Peter Gansevoort Junr Esqr [Provincial Camp at St Johns]"[4]He was also appointed to the 3rd and 4th Provincial Congresses in 1776 and 1777, where the Constitution of the State of New York was adopted on April 20, 1777.