William is believed traditionally to be the son of James Haviland (1553 - 1613), Mayor of Salisbury, England, and Thomassine Maindonail (ca 1560 - 1641).  The only evidence cited is a Christening record in 7 Sep 1606 at St. Thomas's, Salisbury, Wiltshire, England for a "William Havelan." (James had other children by a previous marriage.) This relationship has been debated, with James' brother Thomas being proffered as an alternative father. See Haviland Family Mysteries.
Due to full consideration of all the facts, this profile will, for the time being, maintain William as the son of James until more evidence and information can be found and analyzed.
William appears to have married Hannah Hicks ca 1652, a daughter of John and Horodias (Long) Hicks (a couple who suffered a divorce of notoriety) at Newport, Rhode Island.
father 59 yrs, mother 27 yrs; married Benger/Beanes/Banks?
William Haviland emigrated to America between 1639 - 1646, but probably closer to 1639-1640, for in 1646 he was listed as a Church Warden in Newport, R.I. 
He was recorded as a freeman of Newport in 1653, along with Benedict Arnold (the eventual president and then governor of Rhode Island). In 1655 he was received as Freeman from Newport in a General Election held at Providence, R.I. , very likely to re-elect Roger Williams as President of the Colony of Rhode Island and Providence Plantations, with whom William's views were almost certainly in alignment given his immigration to specifically Rhode Island and his religious beliefs.
On 21 May 1656 he was listed as a Commissioner to the General Court at Portsmouth, R.I., from Newport.  This station should be understood within the context of the political and religious context of Rhode Island at that time.
"While many arrived seeking freedom from religious persecution, unfortunately it continued, and by 1656 some newly arrived Quakers were quite expressive and extreme and sought to exasperate that conflict. William Haviland's colleague Benedict Arnold succeeded Roger Williams as the President of the Colonies, and was forced to respond to these matters. William Haviland, while not a Quaker at this time, was arguably Protestant and probably distressed by the events of that year, given that in the last two generations of his family there were persecutions of Protestants in England. And so he became involved in the local politics wherein the separation of Church and State and freedom of religious expression, for which Roger Williams was a strong proponent and probably William Haviland also, was a major issue.
The appearance of this 'cursed sect of heretics' so alarmed the Puritans that a day of public humiliation was appointedto be held in all the churches mainly on their account. A stringent law was enacted for their suppressionand two years later their tenets were made a capital offence [sic].Fines, imprisonment, whipping, banishment, mutilation, and death, were denounced and inflicted upon them. ... That Rhode Island became a ... refuge for those who fled from this fiery ordeal vexed the United Colonies. The Commissioners, assembled at Boston, wrote a letter urging Rhode Island to banish the Quakers already there and to prohibit any more from coming to the State.  To this request the President and Assistants, met at the Court of trials in Providence, replied, that there was no law by which men could be punished in Rhode Island for their opinions, and that the Quakers being unmolested, were becoming disgusted at their want of success; but that in case of any extravagancies, like those referred to, being committed, the next General Assembly would provide a corrective. That body met at Portsmouth and addressed another letter to the Massachusetts on the same subject. In this letter they say that freedom of conscience was the ground of their charter and shall be maintained; that if the Quakers violate the laws or refuse to conform thereto in any respect, complaint against them will be made in England and the more readily as these people are there tolerated.
There is a reference to grants by Pettaquamscutt land purchases to William Haviland on 1 May 1663. 
William then removed to Long Island, ca 1667, for in that year he purchased 100 acres of land from his brother-in-law, Thomas Hicks, on what is now Little Neck, (then called "Cornbury"). 
On 24 Mar 1685 he signed the renewal-charter of the Patent of Flushing, as did his wife's brother Thomas Hicks. (Flushing is now a township in the borough of Queens, New York, NY.) "The first patent of Incorporation of the Town of Flushing was granted by the Dutch Governor, William Keift, and was dated October 10th, 1645. This was renewed under the English authority. The renewal-charter was dated March 24th, 1685. These manuscripts were probably lost in the fire [of October, 1789, as they were kept in the house of the John Vanderbilt, the Town Clerk, set ablaze deliberately by his slaves]. The only manuscript the Town has, relative to its Incorporation, is termed an "Exemplification of Flushing Patent." It is dated Feb. 24th, 1792; one hundred and seven years after the renewal by the English, and one hundred and forty-seven years after the original grant by the Dutch authorities. We found it in possession of Capt. George B. Roe, who kindly placed a copy at our disposal. It is only sixty-seven years old [as of 1859], but already many parts are nearly obliterated and can with difficulty be deciphered."  William Haviland's name was preserved in this document, as it was a reproduction of the renewal charter of 1685. A "Joseph Havyland" also signed the document. He may be Joseph, son of William.
The Will of Benedict Arnold
William Haviland is mentioned by name in the will of Benedict Arnold, the Governor of Newport, R.I., wherein we find evidence that Arnold purchased land from Haviland and had neighboring (or nearby) property:
...and to her heirs and assigns to have and to hold, possess and enjoy as her and their own true rights and lawful inheritance forever, that is to say, ye lands and tenements hereafter mentioned, namely: ye house and two acres of land, be it more or less, that I bought of William Haviland, being and lying in ye precincts of ye town of Newport, above said, bounded on ye South and on ye East parts on land now or later in the possession of Thomas Clifton or his assigns, on ye West by a highway belonging to said town, and on ye North by land that I have bequeathed to my son Josias Arnold, and I order ye said line of fence to be made and forever maintained by ye occupants of ye premises which I bought of Wm. Haviland aforesaid, as also all that land which I bought of Wm. Vaughan being and lying in ye precincts of the said town of Newport... Unto my beloved son Josiah Arnold aforenamed, I give and bequeath a certain parcell of land, being and lying in ye precincts of ye town of Newport above mentioned, ye said land containing by estimation, four acres more or less, being eight rod in breadth from North to South, and eighty rod in length from East to West, bounded on ye North by land I have bequeathed to his mother Damaris Arnold, &c. on ye East by land of Walter Clarke on ye South in part by land now or late in ye possession of Thomas Clifton or his assigns and partly by ye land above said, I bought of Wm. Haviland and bequeathed to ye said Damaris Arnold, &c....
1639 - 1646: The Passenger and Immigration Lists Index, 1500s-1900s, shows a William Haviland arriving in Rhode Island in 1639. There is little doubt this is our William, though it also has been surmised that he emigrated ca 1641 (after the death of his alleged mother), but no later than 1646 (when he is recorded as a Church Warden in Newport, R.I.).
1646: Recorded as a Church Warden in Newport.
ca 1652: Married Hannah Hicks, daughter of John Hicks & "Herodias" (Long) Hicks.
1653: Recorded as a freeman of Newport, Rhode Island. (There is a record of an "Act and Order of the General Assembly at Newport, May 17, 1653. 'Freemen received of Newport: Benedict Arnold,...' - eventually became governor - '...Joseph Torry,...' - a distant cousin of the Havilands - '...William Haviland, and Jonathan Mott'" ).
ca 1653: son Joseph born.
1656: On 21 May 1656 he is listed as a Commissioner to the General Court at Portsmouth, R.I., from Newport.
167: Representative in Assembly (according to Eduardo Haviland Hillman - but of what town? He states "1667" in a query to the New York Genealogical and Biographical Record , but in the context of Newport, and he certainly had migrated out of Newport by that time. Could be a typographical error, the correct year being 1657?).
1659: son Benjamin born on 3 Apr 1659.
1659 - 1663: At some point in this date range, William probably migrated to Great Neck, or Little Neck, Long Island.
1663: Grants by Pettaquamscutt land purchases to William Haviland
ca 1661: son Jacob born (not known where).
1663: son John born (in Hempstead, Long Island, NY).
1678: William mentioned in the Will of Gov. Benedict Arnold, however apparently after William had long left Newport.
1685: Signed a renewal-charter of the Patent of Flushing, Long Island, NY.
Death & Burial
The location of William Haviland's remains have been researched in Flushing, but without conclusion. It has been suspected that he is buried in the back of the old Meeting House location, where there is a graveyard, but as yet there is no evidence of any marker with his name there. Being a Quaker, he may be buried in an unmarked grave on or near where his property, the precise location of which is not yet identified. Various graveyards throughout Queens have been searched to no avail.
William was born about 1606. He passed away about 1697.
↑Secondary: Hillman, Eduardo Haviland. The New York Genealogical and Biographical Record. Queries. Vol 41. 21 Jan 1910.
Primary Source citations can be found within various Secondary Sources noted above. We need to collect those direct references here. This is a start.
Primary: Letters in regards to land disputes (as re-recorded by Josephine C. Frost from other sources) establish him in the area of Little Neck, Long Island, NY in 1679-1680.
Primary: Will of Gov. Benedict Arnold, dated 1678. Newport Historical Society Library, Special Collections, Newport, RI. (Establishing a William Haviland as a land owner in Newport, RI at an early time)
Secondary: Arnold, Samuel Greene. History of the State of Rhode Island.
Secondary: Torry, Clarence Almon. New England Marriages Prior to 1700. New England Historic Genealogical Society, 1985.
Secondary: James, Sydney V. The Colonial Metamorphoses in Rhode Island and Providence Plantations. Vol. I. New York, NY: D. Appleton & Co., 1859.
Secondary: Mandeville, Henry G. Flushing, Past and Present: A Historical Sketch. Home Lecture Committee of 1857-8 (1860).
Secondary: Onderbonk, Henry Jr. List of Heads of Families in Flushing (French, Dutch and English) from 1645 - 1698, Gathered from Old Records and Documents. ("...Benjamin, John and William Haviland ... Thomas--Justice, and John Hicks..." Benjamin and John as referred to here were very likely the sons of William.)
Secondary: Haviland, Frederick. "The Havilands of Westchester County, New York." New Rochelle, NY. (An appendix in the book Early Wills of Westchester County, New York, from 1664-1784, 1898.)
Special thanks to professional genealogist Penny McKay, official sponsor of the Haviland surname for the Guild of One Name Studies, for research on the original records in the United Kingdom that are related to the Haviland / de Havilland family. (Contact: email@example.com)
It may be possible to confirm family relationships with William by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree: