Who conducts a Jewish marriage ceremony?

Answer 1

The Orthodox wedding has four parts. The first two parts are under the Chuppah (wedding canopy).
Before the ceremony gets underway, the two families meet and agree upon tanaim (what their respective financial support to the couple will be). This may take place at any time before the wedding.
Just prior to the chuppah, the groom, led by the parents, approaches the bride and places a veil upon her which will remain during the chuppah. This is based on a tradition from Jacob.
The first part of the wedding: under the chuppah, the groom gives an item of value (customarily a gold ring) to the bride and, in Hebrew, declares his intention to marry her (see Tosafot commentary, to Talmud Ketubot 3a). Then a blessing is said (Talmud, Ketubot 7b). Technically, this actually constitutes the binding stage of the engagement, and in ancient times was usually done separately from the wedding ceremony.
Between the first and second parts of the wedding, the Rabbi customarily reads aloud the ketubah (marriage contract).
The second part of the wedding: the seven wedding-blessings (see Talmud, Ketubot 8a) are sung over a cup of wine, and the bride and groom take a drink from the cup. Then a glass or plate is broken, to symbolize that even in this happy time, we remain aware of the Destruction of the Temple (see also Tosafot commentary, to Talmud Berakhot 31a).
The third part of the wedding: the bride and groom retire in privacy for several minutes to a room. This constitutes a symbolic consummation and finalizes the formal portion of the marriage. During this seclusion they break the fast which they observed on their wedding day.
The fourth part of the wedding: the couple then enter the adjacent wedding hall, and the festive meal is served to the assembled guests amid a lot of music and dancing (see Talmud, Ketubot 17a).

Answer 2

A rabbi or any Jewish person who is certified by the state to perform a wedding ceremony.

Answer 3

The rabbi or cantor

Answer 4

A Rabbi.

Answer 5

In the United States, most Jewish weddings are conducted by a rabbi or a cantor, but Jewish law (halacha) does not require the presence of clergy, instead, the bride and groom perform the marriage ceremony. Halacha does require is at least two reliable Jewish witnesses who know the ceremony and can attest that the wedding was performed properly. However, Halacha also states that the law of the land is binding, so if the local government requires clergy, so be it. In states that allow common-law marriage, the Jewish requirement for witnesses usually meets the legal requirement.