a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, ij (or y), z
Some Dutch dictionaries and lists (such as ten year tables) place words or names that start wih the "IJ" between the "I" and "J" and not where the "Y" is usually found.
The letter 'x' is rarely seen in Dutch script, as it is only used in words borrowed from other language. This is also the case with the Y.
The letter 'ij' is considered as a single character with a sound like. The 'y' and 'ij' can be interchangeable especially in the 16th century.
Here are examples of letters found in old Dutch documents from Family Search.